perplexus.info :: Just Math : Root sum equals integer

Root sum equals integer (Posted on 2015-03-10)

Find all integers n for which √(25/2 + √(625/4 –n)) + √(25/2 - √(625/4 –n)) is an integer.

No Solution Yet Submitted by K Sengupta

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re(3): solution & playing around

| Comment 5 of 7 |

n=4k^4+8k^3-44k^2-48k+144 gives valid results for all integers k of 2 or more. k=1 gives spurious n=64.

My (2*p^2 + 10p)^2, from my first post, gives valid results for all integers zero or more.

Posted by Charlie on 2015-03-10 15:54:20

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