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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The corresponding x-values are in A230710.

LINKS

Zak Seidov, Table of n, a(n) for n = 1..200

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

Cf. A000351, A188949, A230623, A230645, A230710.

Sequence in context: A292157 A256801 A103669 * A034485 A018006 A183510

Adjacent sequences:  A230708 A230709 A230710 * A230712 A230713 A230714

KEYWORD

nonn

AUTHOR

Colin Barker, Oct 28 2013

STATUS

approved

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Last modified August 1 03:52 EDT 2021. Contains 346384 sequences. (Running on oeis4.)