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A230711
Values of y such that x^2 + y^2 = 5^n with x and y coprime and 0 < x < y.
7
2, 4, 11, 24, 41, 117, 278, 527, 1199, 3116, 6469, 11753, 33802, 76443, 136762, 354144, 873121, 1721764, 3565918, 9653287, 20783558, 34867797, 103232189, 242017776, 451910159, 1064447283, 2726446322, 5583548873, 10513816601, 29729597084, 66349305331
OFFSET
1,1
COMMENTS
The corresponding x-values are in A230710.
LINKS
Chris Busenhart, Lorenz Halbeisen, Norbert Hungerbühler, Oliver Riesen, On primitive solutions of the Diophantine equation x^2+ y^2= M, Eidgenössische Technische Hochschule (ETH Zürich, Switzerland, 2020).
EXAMPLE
a(4)=24 because 7^2+24^2=625=5^4.
MATHEMATICA
Table[Select[PowersRepresentations[5^n, 2, 2], CoprimeQ[#[[1]], #[[2]]] &][[1, 2]], {n, 33}] (* T. D. Noe, Nov 04 2013 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Colin Barker, Oct 28 2013
STATUS
approved