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Near powers (Posted on 2023-09-28) Difficulty: 3 of 5

If n^2+7=a^5, and n^3-516=b^2, with a,b,n all positive integers, find a,b, and n.

Prove this solution is unique.

No Solution Yet Submitted by broll    
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Some Thoughts Answer without proof of uniqueness | Comment 1 of 2
181^2 + 7 = 8^5 
181^3 - 516 = 2435^2

(a,b,n) = (8, 2435, 181)
-------
squares = [i**2 for i in range(10000)]
fifths = [i**5 for i in range(10000)]
for n in range(100000):
    if n**2 + 7 in fifths  and n**3 - 516 in squares:
        print(n, n**2+7, (n**2+7)**.2, n**3-516, (n**3-516)**.5)

Program output:
181 32768 8.000000000000002 5929225 2435.0

[Edited to add program output and second equation]

Edited on September 28, 2023, 3:01 pm
  Posted by Larry on 2023-09-28 12:26:03

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