|
%I #20 Oct 09 2014 16:49:58
%S 1,12,14,14,25,27,25,14,1,40,1,27,38,40,12,14,1,53,14,1,51,40,27,64,
%T 64,14,66,64,77,77,79,66,79,77,25,38,77,40,1,79,64,53,12,92,90,51,66,
%U 77,25,64,92,77,1,79,64,53,1,103,38,12,14,53,1,77,116,79,116,92,118,118,77,103,66,118,38
%N Values of x in equation A142508(n)=x^2+13y^2.
%e a(1)=1 because A142508(1)=53=1^2+13*2^2 (x=1,y=2);
%e a(2)=12 because A142508(2)=157=12^2+13*1^2 (x=12, y=1).
%t f[n_] := FindInstance[n == x^2 + 13 y^2 && x > 0 && y > 0, {x, y}, Integers][[1, 1, 2]]; f@# & /@ Select[ Prime@ Range@ 1840, Mod[#, 52] == 1 &] (* _Robert G. Wilson v_, Oct 06 2014 *)
%Y Cf. A033210, A142508, A248221, A248019(values of y).
%K nonn
%O 1,2
%A _Zak Seidov_, Oct 06 2014
|
