A175556 Numbers n such that n^7 is the sum of a positive fifth power and a square: n^7=x^5+y^2, with repetition.

8, 9, 98, 108, 125, 196, 225, 576, 676, 864, 900, 1000, 1352, 1568, 1568, 1764, 2000, 2601, 3087, 3993, 4232, 4418, 4913, 5324, 5400, 6348, 7225, 7776, 8100, 8100, 8192, 9216, 12348, 12482, 15123, 15376, 15552, 16464, 16928, 17576, 18225

Offset

1,1

Links

Table of n, a(n) for n=1..41.

Zak Seidov, List of triples n, x, y

Example

8^7=16^5+1024^2=2097152, 9^7=18^5+1701^2=4782969.

Prog

(PARI) a175556_print(n) = {local(xm, n7, r, x); if(n < 2, return(0)); xm = floor(n^(7/5)); n7 = n^7; for(x = 1, xm, r = n7 - x^5; if(issquare(r) && r > 0, print(n)))} \\ Michael B. Porter, Sep 22 2015

Crossrefs

Sequence in context: A256341 A116249 A256162 * A165467 A239584 A041141

Adjacent sequences: A175553 A175554 A175555 * A175557 A175558 A175559

Keyword

nonn

Author

Zak Seidov, Jun 29 2010

Status

approved