A033772 - OEIS

%I #17 May 31 2017 03:09:41

%S 1,1,0,1,0,0,1,0,0,0,1,0,0,1,1,1,1,0,0,1,0,1,0,1,0,0,0,0,2,0,0,0,0,0,

%T 1,0,1,0,0,1,1,1,1,0,0,2,0,0,0,2,0,0,0,0,1,1,0,0,1,0,1,0,0,0,0,0,1,1,

%U 1,0,0,0,0,0,0,1,0,0,2,2,0,1,0,0,2,0,0,0

%N Product t2(q^d); d | 13, where t2 = theta2(q)/(2*q^(1/4)).

%C Also the number of positive odd solutions to equation x^2 + 13*y^2 = 8*n + 14. - _Seiichi Manyama_, May 28 2017

%H Seiichi Manyama, <a href="/A033772/b033772.txt">Table of n, a(n) for n = 0..10000</a>

%t QP=QPochhammer; s=QP[q^2]^2 (QP[q^26]^2 / (QP[q] QP[q^13]))+O[q]^105; CoefficientList[s, q] (* _Vincenzo Librandi_, May 31 2017 *)

%K nonn

%O 0,29

%A _N. J. A. Sloane_

%E More terms from _Seiichi Manyama_, May 22 2017