A230623 Values of y such that x^2 + y^2 = 17^n with x and y coprime and 0 < x < y.

4, 15, 52, 240, 1121, 4888, 20047, 77280, 277441, 1093425, 5279468, 23647519, 99429196, 393425745, 1457109628, 4968639359, 24553864319, 113193708472, 488133974353, 1980778750800, 7547952442399, 26710380775592, 112605054449252

Offset

1,1

Comments

The corresponding x-values are in A230622.

Links

Vincenzo Librandi, 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(2)=15 because 8^2 + 15^2 = 289 = 17^2.

Mathematica

Table[Select[PowersRepresentations[17^n, 2, 2], CoprimeQ@@#&][[1, 2]], {n, 1, 40}] (* Vincenzo Librandi, Mar 02 2014 *)

Crossrefs

Cf. A001026, A188949, A230622.

Sequence in context: A371217 A208722 A057332 * A162978 A171309 A210781

Adjacent sequences: A230620 A230621 A230622 * A230624 A230625 A230626

Keyword

nonn

Author

Colin Barker, Oct 26 2013

Status

approved