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Pietro Majer
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I am working a combinatorial question. I need to decide when the following function m(7m^2 - 22m +7)/sqrt((m^2- 2m + 9)(9m^2 - 2m +1)) takes$$\frac{m(7m^2 - 22m +7)}{ \sqrt{ (m^2- 2m + 9)(9m^2 - 2m +1) } } $$takes integer values with following assumption:

  1. m takes all positive integer values
  2. (m^2- 2m + 9)(9m^2 - 2m +1) is a perfect square(= n^2 for some integer n).

1) m takes all positive integer values; 2) $(m^2- 2m + 9)(9m^2 - 2m +1)$ is a perfect square (= $n^2$ for some integer $n$). Limited computation for m < 20000$m < 20000$ shows m = 1, 5$m = 1, 5$.

Many thanks, Jianmin

I am working a combinatorial question. I need to decide when the following function m(7m^2 - 22m +7)/sqrt((m^2- 2m + 9)(9m^2 - 2m +1)) takes integer values with following assumption:

  1. m takes all positive integer values
  2. (m^2- 2m + 9)(9m^2 - 2m +1) is a perfect square(= n^2 for some integer n).

Limited computation for m < 20000 shows m = 1, 5.

Many thanks, Jianmin

I am working a combinatorial question. I need to decide when the following function $$\frac{m(7m^2 - 22m +7)}{ \sqrt{ (m^2- 2m + 9)(9m^2 - 2m +1) } } $$takes integer values with following assumption: 1) m takes all positive integer values; 2) $(m^2- 2m + 9)(9m^2 - 2m +1)$ is a perfect square (= $n^2$ for some integer $n$). Limited computation for $m < 20000$ shows $m = 1, 5$.

Many thanks, Jianmin

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user15582
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How to decide this function takes integer values?

I am working a combinatorial question. I need to decide when the following function m(7m^2 - 22m +7)/sqrt((m^2- 2m + 9)(9m^2 - 2m +1)) takes integer values with following assumption:

  1. m takes all positive integer values
  2. (m^2- 2m + 9)(9m^2 - 2m +1) is a perfect square(= n^2 for some integer n).

Limited computation for m < 20000 shows m = 1, 5.

Many thanks, Jianmin