Multiplying to make sorted sequence - limit on multiplicand

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Given a list of positive integers $ x_1, x_2, x_3, ldots, x_n $, we can find positive integer coefficients
$ c_1, c_2, c_3, ldots, c_n $ such that



$$ c_1x_1 lt c_2x_2 lt c_3x_3 lt ldots lt c_nx_n $$



(For eg., for $ 5, 4, 12, 1, 3 $, the coefficients $ 1, 2, 1, 13, 5 $ produce the increasing list $ 5, 8, 12, 13, 15 $.)



There is a smallest (i.e. least in value) set* of such coefficients for a given list. What is an upper bound, in terms of values in the given list, on the largest coefficient in such a minimum-value set of coefficients?



* By smallest, what I have in mind is the result of this iterative process:

$ c_1 = 1 $.

$ c_2 $ is the smallest positive integer such that $ c_2 x_2 gt x_1 $.

$ c_3 $ is the smallest positive integer such that $ c_3 x_3 gt c_2 x_2 $.

$ c_4 $ is the smallest positive integer such that $ c_4 x_4 gt c_3 x_3 $.

And so on.

I think this might be the same as saying the set of coefficients with the least sum, but in case it is not, the above is the actual expected answer.







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  • Questions : 1) are $c_1,dots,c_n$ supposed to be integers ? 2) If this is the case, what good order do you define on $mathbb N^n$ to define your "smallest" set of integers ?
    – Nicolas FRANCOIS
    Aug 6 at 0:22










  • @NicolasFRANCOIS 1) Yes, updated the question on that. 2) I was afraid someone was going to ask that! I think what I need is the same as the set of such integer coefficients with the smallest sum, but I'll update the question with details.
    – sundar
    Aug 6 at 0:27










  • If any of the $c$s is $1$ you can ignore everything before it when considering the later part. You clearly get the largest $c$ by having $x_n=1$ and working the numbers before it to make $c_n-1x_n-1$ as large as possible.
    – Ross Millikan
    Aug 6 at 0:31










  • One "measure" of the largeness of your coefficients could be $max_k c_k$, in which case your "algorithm" may not be optimal...
    – Nicolas FRANCOIS
    Aug 6 at 0:56














up vote
1
down vote

favorite
1












Given a list of positive integers $ x_1, x_2, x_3, ldots, x_n $, we can find positive integer coefficients
$ c_1, c_2, c_3, ldots, c_n $ such that



$$ c_1x_1 lt c_2x_2 lt c_3x_3 lt ldots lt c_nx_n $$



(For eg., for $ 5, 4, 12, 1, 3 $, the coefficients $ 1, 2, 1, 13, 5 $ produce the increasing list $ 5, 8, 12, 13, 15 $.)



There is a smallest (i.e. least in value) set* of such coefficients for a given list. What is an upper bound, in terms of values in the given list, on the largest coefficient in such a minimum-value set of coefficients?



* By smallest, what I have in mind is the result of this iterative process:

$ c_1 = 1 $.

$ c_2 $ is the smallest positive integer such that $ c_2 x_2 gt x_1 $.

$ c_3 $ is the smallest positive integer such that $ c_3 x_3 gt c_2 x_2 $.

$ c_4 $ is the smallest positive integer such that $ c_4 x_4 gt c_3 x_3 $.

And so on.

I think this might be the same as saying the set of coefficients with the least sum, but in case it is not, the above is the actual expected answer.







share|cite|improve this question





















  • Questions : 1) are $c_1,dots,c_n$ supposed to be integers ? 2) If this is the case, what good order do you define on $mathbb N^n$ to define your "smallest" set of integers ?
    – Nicolas FRANCOIS
    Aug 6 at 0:22










  • @NicolasFRANCOIS 1) Yes, updated the question on that. 2) I was afraid someone was going to ask that! I think what I need is the same as the set of such integer coefficients with the smallest sum, but I'll update the question with details.
    – sundar
    Aug 6 at 0:27










  • If any of the $c$s is $1$ you can ignore everything before it when considering the later part. You clearly get the largest $c$ by having $x_n=1$ and working the numbers before it to make $c_n-1x_n-1$ as large as possible.
    – Ross Millikan
    Aug 6 at 0:31










  • One "measure" of the largeness of your coefficients could be $max_k c_k$, in which case your "algorithm" may not be optimal...
    – Nicolas FRANCOIS
    Aug 6 at 0:56












up vote
1
down vote

favorite
1









up vote
1
down vote

favorite
1






1





Given a list of positive integers $ x_1, x_2, x_3, ldots, x_n $, we can find positive integer coefficients
$ c_1, c_2, c_3, ldots, c_n $ such that



$$ c_1x_1 lt c_2x_2 lt c_3x_3 lt ldots lt c_nx_n $$



(For eg., for $ 5, 4, 12, 1, 3 $, the coefficients $ 1, 2, 1, 13, 5 $ produce the increasing list $ 5, 8, 12, 13, 15 $.)



There is a smallest (i.e. least in value) set* of such coefficients for a given list. What is an upper bound, in terms of values in the given list, on the largest coefficient in such a minimum-value set of coefficients?



* By smallest, what I have in mind is the result of this iterative process:

$ c_1 = 1 $.

$ c_2 $ is the smallest positive integer such that $ c_2 x_2 gt x_1 $.

$ c_3 $ is the smallest positive integer such that $ c_3 x_3 gt c_2 x_2 $.

$ c_4 $ is the smallest positive integer such that $ c_4 x_4 gt c_3 x_3 $.

And so on.

I think this might be the same as saying the set of coefficients with the least sum, but in case it is not, the above is the actual expected answer.







share|cite|improve this question













Given a list of positive integers $ x_1, x_2, x_3, ldots, x_n $, we can find positive integer coefficients
$ c_1, c_2, c_3, ldots, c_n $ such that



$$ c_1x_1 lt c_2x_2 lt c_3x_3 lt ldots lt c_nx_n $$



(For eg., for $ 5, 4, 12, 1, 3 $, the coefficients $ 1, 2, 1, 13, 5 $ produce the increasing list $ 5, 8, 12, 13, 15 $.)



There is a smallest (i.e. least in value) set* of such coefficients for a given list. What is an upper bound, in terms of values in the given list, on the largest coefficient in such a minimum-value set of coefficients?



* By smallest, what I have in mind is the result of this iterative process:

$ c_1 = 1 $.

$ c_2 $ is the smallest positive integer such that $ c_2 x_2 gt x_1 $.

$ c_3 $ is the smallest positive integer such that $ c_3 x_3 gt c_2 x_2 $.

$ c_4 $ is the smallest positive integer such that $ c_4 x_4 gt c_3 x_3 $.

And so on.

I think this might be the same as saying the set of coefficients with the least sum, but in case it is not, the above is the actual expected answer.









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share|cite|improve this question




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edited Aug 6 at 0:34
























asked Aug 5 at 23:59









sundar

1166




1166











  • Questions : 1) are $c_1,dots,c_n$ supposed to be integers ? 2) If this is the case, what good order do you define on $mathbb N^n$ to define your "smallest" set of integers ?
    – Nicolas FRANCOIS
    Aug 6 at 0:22










  • @NicolasFRANCOIS 1) Yes, updated the question on that. 2) I was afraid someone was going to ask that! I think what I need is the same as the set of such integer coefficients with the smallest sum, but I'll update the question with details.
    – sundar
    Aug 6 at 0:27










  • If any of the $c$s is $1$ you can ignore everything before it when considering the later part. You clearly get the largest $c$ by having $x_n=1$ and working the numbers before it to make $c_n-1x_n-1$ as large as possible.
    – Ross Millikan
    Aug 6 at 0:31










  • One "measure" of the largeness of your coefficients could be $max_k c_k$, in which case your "algorithm" may not be optimal...
    – Nicolas FRANCOIS
    Aug 6 at 0:56
















  • Questions : 1) are $c_1,dots,c_n$ supposed to be integers ? 2) If this is the case, what good order do you define on $mathbb N^n$ to define your "smallest" set of integers ?
    – Nicolas FRANCOIS
    Aug 6 at 0:22










  • @NicolasFRANCOIS 1) Yes, updated the question on that. 2) I was afraid someone was going to ask that! I think what I need is the same as the set of such integer coefficients with the smallest sum, but I'll update the question with details.
    – sundar
    Aug 6 at 0:27










  • If any of the $c$s is $1$ you can ignore everything before it when considering the later part. You clearly get the largest $c$ by having $x_n=1$ and working the numbers before it to make $c_n-1x_n-1$ as large as possible.
    – Ross Millikan
    Aug 6 at 0:31










  • One "measure" of the largeness of your coefficients could be $max_k c_k$, in which case your "algorithm" may not be optimal...
    – Nicolas FRANCOIS
    Aug 6 at 0:56















Questions : 1) are $c_1,dots,c_n$ supposed to be integers ? 2) If this is the case, what good order do you define on $mathbb N^n$ to define your "smallest" set of integers ?
– Nicolas FRANCOIS
Aug 6 at 0:22




Questions : 1) are $c_1,dots,c_n$ supposed to be integers ? 2) If this is the case, what good order do you define on $mathbb N^n$ to define your "smallest" set of integers ?
– Nicolas FRANCOIS
Aug 6 at 0:22












@NicolasFRANCOIS 1) Yes, updated the question on that. 2) I was afraid someone was going to ask that! I think what I need is the same as the set of such integer coefficients with the smallest sum, but I'll update the question with details.
– sundar
Aug 6 at 0:27




@NicolasFRANCOIS 1) Yes, updated the question on that. 2) I was afraid someone was going to ask that! I think what I need is the same as the set of such integer coefficients with the smallest sum, but I'll update the question with details.
– sundar
Aug 6 at 0:27












If any of the $c$s is $1$ you can ignore everything before it when considering the later part. You clearly get the largest $c$ by having $x_n=1$ and working the numbers before it to make $c_n-1x_n-1$ as large as possible.
– Ross Millikan
Aug 6 at 0:31




If any of the $c$s is $1$ you can ignore everything before it when considering the later part. You clearly get the largest $c$ by having $x_n=1$ and working the numbers before it to make $c_n-1x_n-1$ as large as possible.
– Ross Millikan
Aug 6 at 0:31












One "measure" of the largeness of your coefficients could be $max_k c_k$, in which case your "algorithm" may not be optimal...
– Nicolas FRANCOIS
Aug 6 at 0:56




One "measure" of the largeness of your coefficients could be $max_k c_k$, in which case your "algorithm" may not be optimal...
– Nicolas FRANCOIS
Aug 6 at 0:56










2 Answers
2






active

oldest

votes

















up vote
1
down vote



accepted










With your "algorithm", you have, for all $k$, by choosing the least possible $c_k+1$ ($lfloor xrfloor$ being the greatest integer lower than $x$):
$$c_k+1=leftlfloorfracc_kx_kx_k+1rightrfloor+1le fracc_kx_kx_k+1+1$$
So for example :
$$c_2le fracc_1x_1x_2+1 = fracx_1+x_2x_2$$
$$c_3le fracc_2x_2x_3+1=fracx_1+x_2+x_3x_3$$
And so on. More generally :
$$(forall k) c_kle fracx_1+x_2+dots+x_kx_k$$
So one simple majoration for your coefficients is :
$$(forall k) c_kle sum_i=1^n x_i$$
Is that the kind of majoration you are looking for ?






share|cite|improve this answer





















  • Yes, that's exactly the sort of bound I was looking for. Good that it comes down to a nicely simple expression. Thank you!
    – sundar
    Aug 6 at 1:05










  • This wasn't part of the question so feel free to ignore it, but: what would be an upper bound on the largest (i.e. final) value in the list resulting from the multiplication? One obvious one is $ x_n $ multiplied by the above summation, but is there a tighter bound than that?
    – sundar
    Aug 6 at 1:16











  • As Ross answer showed, the sum of all values seems to be reachable for a particular set of values $(x_1,dots,x_n)$, so my upper bound looks accurate :-)
    – Nicolas FRANCOIS
    Aug 6 at 2:46

















up vote
0
down vote













If any of the $x_i$ are large enough that we can get away with $c_i=1$ it essentially breaks the sequence. We can ignore all the $x$'s before and start the sequence there. If we start with some number for $x_1$ we can imagine choosing the rest of the $x$s to make the products as large as possible while not having any $c_i$ except the last be $1$. We want $x_2=x_1-1$, which gives $c_2=2$ and the second product is $2(x_1-1)$. The pattern continues with $x_3=2(x_1-1)-1, c_3=2,$ product $4x_1-6$. Then $x_4=4x_1-7,$ product $8x_1-14$. We get that the $k^th$ product is $2^k-1x_1-2^k+1+2$. Finally we choose $x_n=1$, which forces $c_n=2^n-2x_1-2^n+3$. I think that is as large as you can force for the given $x_1$. All the $c$s except the first and last are $2$. Starting with $x_1=10$ and letting $n=8$ we get the following
$$begin array r r r ri&x_i&c_i&x_ic_i\ hline1&10&1&10\
2&9&2&18\3&17&2&34\4&33&2&66\5&65&2&130\6&129&2&258\7&257&2&514\8&1&515&515 end array$$






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    2 Answers
    2






    active

    oldest

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    2 Answers
    2






    active

    oldest

    votes









    active

    oldest

    votes






    active

    oldest

    votes








    up vote
    1
    down vote



    accepted










    With your "algorithm", you have, for all $k$, by choosing the least possible $c_k+1$ ($lfloor xrfloor$ being the greatest integer lower than $x$):
    $$c_k+1=leftlfloorfracc_kx_kx_k+1rightrfloor+1le fracc_kx_kx_k+1+1$$
    So for example :
    $$c_2le fracc_1x_1x_2+1 = fracx_1+x_2x_2$$
    $$c_3le fracc_2x_2x_3+1=fracx_1+x_2+x_3x_3$$
    And so on. More generally :
    $$(forall k) c_kle fracx_1+x_2+dots+x_kx_k$$
    So one simple majoration for your coefficients is :
    $$(forall k) c_kle sum_i=1^n x_i$$
    Is that the kind of majoration you are looking for ?






    share|cite|improve this answer





















    • Yes, that's exactly the sort of bound I was looking for. Good that it comes down to a nicely simple expression. Thank you!
      – sundar
      Aug 6 at 1:05










    • This wasn't part of the question so feel free to ignore it, but: what would be an upper bound on the largest (i.e. final) value in the list resulting from the multiplication? One obvious one is $ x_n $ multiplied by the above summation, but is there a tighter bound than that?
      – sundar
      Aug 6 at 1:16











    • As Ross answer showed, the sum of all values seems to be reachable for a particular set of values $(x_1,dots,x_n)$, so my upper bound looks accurate :-)
      – Nicolas FRANCOIS
      Aug 6 at 2:46














    up vote
    1
    down vote



    accepted










    With your "algorithm", you have, for all $k$, by choosing the least possible $c_k+1$ ($lfloor xrfloor$ being the greatest integer lower than $x$):
    $$c_k+1=leftlfloorfracc_kx_kx_k+1rightrfloor+1le fracc_kx_kx_k+1+1$$
    So for example :
    $$c_2le fracc_1x_1x_2+1 = fracx_1+x_2x_2$$
    $$c_3le fracc_2x_2x_3+1=fracx_1+x_2+x_3x_3$$
    And so on. More generally :
    $$(forall k) c_kle fracx_1+x_2+dots+x_kx_k$$
    So one simple majoration for your coefficients is :
    $$(forall k) c_kle sum_i=1^n x_i$$
    Is that the kind of majoration you are looking for ?






    share|cite|improve this answer





















    • Yes, that's exactly the sort of bound I was looking for. Good that it comes down to a nicely simple expression. Thank you!
      – sundar
      Aug 6 at 1:05










    • This wasn't part of the question so feel free to ignore it, but: what would be an upper bound on the largest (i.e. final) value in the list resulting from the multiplication? One obvious one is $ x_n $ multiplied by the above summation, but is there a tighter bound than that?
      – sundar
      Aug 6 at 1:16











    • As Ross answer showed, the sum of all values seems to be reachable for a particular set of values $(x_1,dots,x_n)$, so my upper bound looks accurate :-)
      – Nicolas FRANCOIS
      Aug 6 at 2:46












    up vote
    1
    down vote



    accepted







    up vote
    1
    down vote



    accepted






    With your "algorithm", you have, for all $k$, by choosing the least possible $c_k+1$ ($lfloor xrfloor$ being the greatest integer lower than $x$):
    $$c_k+1=leftlfloorfracc_kx_kx_k+1rightrfloor+1le fracc_kx_kx_k+1+1$$
    So for example :
    $$c_2le fracc_1x_1x_2+1 = fracx_1+x_2x_2$$
    $$c_3le fracc_2x_2x_3+1=fracx_1+x_2+x_3x_3$$
    And so on. More generally :
    $$(forall k) c_kle fracx_1+x_2+dots+x_kx_k$$
    So one simple majoration for your coefficients is :
    $$(forall k) c_kle sum_i=1^n x_i$$
    Is that the kind of majoration you are looking for ?






    share|cite|improve this answer













    With your "algorithm", you have, for all $k$, by choosing the least possible $c_k+1$ ($lfloor xrfloor$ being the greatest integer lower than $x$):
    $$c_k+1=leftlfloorfracc_kx_kx_k+1rightrfloor+1le fracc_kx_kx_k+1+1$$
    So for example :
    $$c_2le fracc_1x_1x_2+1 = fracx_1+x_2x_2$$
    $$c_3le fracc_2x_2x_3+1=fracx_1+x_2+x_3x_3$$
    And so on. More generally :
    $$(forall k) c_kle fracx_1+x_2+dots+x_kx_k$$
    So one simple majoration for your coefficients is :
    $$(forall k) c_kle sum_i=1^n x_i$$
    Is that the kind of majoration you are looking for ?







    share|cite|improve this answer













    share|cite|improve this answer



    share|cite|improve this answer











    answered Aug 6 at 0:54









    Nicolas FRANCOIS

    3,2501415




    3,2501415











    • Yes, that's exactly the sort of bound I was looking for. Good that it comes down to a nicely simple expression. Thank you!
      – sundar
      Aug 6 at 1:05










    • This wasn't part of the question so feel free to ignore it, but: what would be an upper bound on the largest (i.e. final) value in the list resulting from the multiplication? One obvious one is $ x_n $ multiplied by the above summation, but is there a tighter bound than that?
      – sundar
      Aug 6 at 1:16











    • As Ross answer showed, the sum of all values seems to be reachable for a particular set of values $(x_1,dots,x_n)$, so my upper bound looks accurate :-)
      – Nicolas FRANCOIS
      Aug 6 at 2:46
















    • Yes, that's exactly the sort of bound I was looking for. Good that it comes down to a nicely simple expression. Thank you!
      – sundar
      Aug 6 at 1:05










    • This wasn't part of the question so feel free to ignore it, but: what would be an upper bound on the largest (i.e. final) value in the list resulting from the multiplication? One obvious one is $ x_n $ multiplied by the above summation, but is there a tighter bound than that?
      – sundar
      Aug 6 at 1:16











    • As Ross answer showed, the sum of all values seems to be reachable for a particular set of values $(x_1,dots,x_n)$, so my upper bound looks accurate :-)
      – Nicolas FRANCOIS
      Aug 6 at 2:46















    Yes, that's exactly the sort of bound I was looking for. Good that it comes down to a nicely simple expression. Thank you!
    – sundar
    Aug 6 at 1:05




    Yes, that's exactly the sort of bound I was looking for. Good that it comes down to a nicely simple expression. Thank you!
    – sundar
    Aug 6 at 1:05












    This wasn't part of the question so feel free to ignore it, but: what would be an upper bound on the largest (i.e. final) value in the list resulting from the multiplication? One obvious one is $ x_n $ multiplied by the above summation, but is there a tighter bound than that?
    – sundar
    Aug 6 at 1:16





    This wasn't part of the question so feel free to ignore it, but: what would be an upper bound on the largest (i.e. final) value in the list resulting from the multiplication? One obvious one is $ x_n $ multiplied by the above summation, but is there a tighter bound than that?
    – sundar
    Aug 6 at 1:16













    As Ross answer showed, the sum of all values seems to be reachable for a particular set of values $(x_1,dots,x_n)$, so my upper bound looks accurate :-)
    – Nicolas FRANCOIS
    Aug 6 at 2:46




    As Ross answer showed, the sum of all values seems to be reachable for a particular set of values $(x_1,dots,x_n)$, so my upper bound looks accurate :-)
    – Nicolas FRANCOIS
    Aug 6 at 2:46










    up vote
    0
    down vote













    If any of the $x_i$ are large enough that we can get away with $c_i=1$ it essentially breaks the sequence. We can ignore all the $x$'s before and start the sequence there. If we start with some number for $x_1$ we can imagine choosing the rest of the $x$s to make the products as large as possible while not having any $c_i$ except the last be $1$. We want $x_2=x_1-1$, which gives $c_2=2$ and the second product is $2(x_1-1)$. The pattern continues with $x_3=2(x_1-1)-1, c_3=2,$ product $4x_1-6$. Then $x_4=4x_1-7,$ product $8x_1-14$. We get that the $k^th$ product is $2^k-1x_1-2^k+1+2$. Finally we choose $x_n=1$, which forces $c_n=2^n-2x_1-2^n+3$. I think that is as large as you can force for the given $x_1$. All the $c$s except the first and last are $2$. Starting with $x_1=10$ and letting $n=8$ we get the following
    $$begin array r r r ri&x_i&c_i&x_ic_i\ hline1&10&1&10\
    2&9&2&18\3&17&2&34\4&33&2&66\5&65&2&130\6&129&2&258\7&257&2&514\8&1&515&515 end array$$






    share|cite|improve this answer



























      up vote
      0
      down vote













      If any of the $x_i$ are large enough that we can get away with $c_i=1$ it essentially breaks the sequence. We can ignore all the $x$'s before and start the sequence there. If we start with some number for $x_1$ we can imagine choosing the rest of the $x$s to make the products as large as possible while not having any $c_i$ except the last be $1$. We want $x_2=x_1-1$, which gives $c_2=2$ and the second product is $2(x_1-1)$. The pattern continues with $x_3=2(x_1-1)-1, c_3=2,$ product $4x_1-6$. Then $x_4=4x_1-7,$ product $8x_1-14$. We get that the $k^th$ product is $2^k-1x_1-2^k+1+2$. Finally we choose $x_n=1$, which forces $c_n=2^n-2x_1-2^n+3$. I think that is as large as you can force for the given $x_1$. All the $c$s except the first and last are $2$. Starting with $x_1=10$ and letting $n=8$ we get the following
      $$begin array r r r ri&x_i&c_i&x_ic_i\ hline1&10&1&10\
      2&9&2&18\3&17&2&34\4&33&2&66\5&65&2&130\6&129&2&258\7&257&2&514\8&1&515&515 end array$$






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        If any of the $x_i$ are large enough that we can get away with $c_i=1$ it essentially breaks the sequence. We can ignore all the $x$'s before and start the sequence there. If we start with some number for $x_1$ we can imagine choosing the rest of the $x$s to make the products as large as possible while not having any $c_i$ except the last be $1$. We want $x_2=x_1-1$, which gives $c_2=2$ and the second product is $2(x_1-1)$. The pattern continues with $x_3=2(x_1-1)-1, c_3=2,$ product $4x_1-6$. Then $x_4=4x_1-7,$ product $8x_1-14$. We get that the $k^th$ product is $2^k-1x_1-2^k+1+2$. Finally we choose $x_n=1$, which forces $c_n=2^n-2x_1-2^n+3$. I think that is as large as you can force for the given $x_1$. All the $c$s except the first and last are $2$. Starting with $x_1=10$ and letting $n=8$ we get the following
        $$begin array r r r ri&x_i&c_i&x_ic_i\ hline1&10&1&10\
        2&9&2&18\3&17&2&34\4&33&2&66\5&65&2&130\6&129&2&258\7&257&2&514\8&1&515&515 end array$$






        share|cite|improve this answer















        If any of the $x_i$ are large enough that we can get away with $c_i=1$ it essentially breaks the sequence. We can ignore all the $x$'s before and start the sequence there. If we start with some number for $x_1$ we can imagine choosing the rest of the $x$s to make the products as large as possible while not having any $c_i$ except the last be $1$. We want $x_2=x_1-1$, which gives $c_2=2$ and the second product is $2(x_1-1)$. The pattern continues with $x_3=2(x_1-1)-1, c_3=2,$ product $4x_1-6$. Then $x_4=4x_1-7,$ product $8x_1-14$. We get that the $k^th$ product is $2^k-1x_1-2^k+1+2$. Finally we choose $x_n=1$, which forces $c_n=2^n-2x_1-2^n+3$. I think that is as large as you can force for the given $x_1$. All the $c$s except the first and last are $2$. Starting with $x_1=10$ and letting $n=8$ we get the following
        $$begin array r r r ri&x_i&c_i&x_ic_i\ hline1&10&1&10\
        2&9&2&18\3&17&2&34\4&33&2&66\5&65&2&130\6&129&2&258\7&257&2&514\8&1&515&515 end array$$







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        edited Aug 6 at 0:53


























        answered Aug 6 at 0:45









        Ross Millikan

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        276k21187352






















             

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