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Values of x such that x^2 + y^2 = 61^n with x and y coprime and 0 < x < y.
3

%I #15 Mar 03 2014 02:46:18

%S 5,11,234,1320,9475,117469,266286,9184560,3302155,520632300,

%T 1387108806,23922442439,154165737965,933420304380,13338456688674,

%U 22995028210081,1026964091673115,713853567388260,54078566783400895,171226928056302601,2435077776719657394

%N Values of x such that x^2 + y^2 = 61^n with x and y coprime and 0 < x < y.

%C The corresponding y-values are in A230842.

%H Vincenzo Librandi, <a href="/A230841/b230841.txt">Table of n, a(n) for n = 1..200</a>

%e a(3)=234 because 234^2+415^2=226981=61^3.

%t Table[Select[PowersRepresentations[61^n, 2, 2], CoprimeQ[#[[1]], #[[2]]] &][[1, 1]], {n, 22}] (* _T. D. Noe_, Nov 04 2013 *)

%t Table[Select[PowersRepresentations[61^n, 2, 2], CoprimeQ@@#&][[1, 1]], {n, 1, 40}] (* _Vincenzo Librandi_, Mar 02 2014 *)

%Y Cf. A230842, A188948, A230622, A230644, A230710, A230712, A230743, A230759.

%K nonn

%O 1,1

%A _Colin Barker_, Oct 31 2013

%E a(10) and a(20) corrected by _Zak Seidov_, Nov 02 2013