login
Number of integer solutions to a^2 + 2*b^2 + 2*c^2 + 2*d^2 = n.
7

%I #12 Oct 08 2018 03:50:01

%S 1,2,6,12,14,24,20,16,30,14,40,60,36,72,48,16,62,36,42,108,72,96,100,

%T 48,68,42,120,120,112,168,48,64,126,40,108,192,98,216,180,48,136,84,

%U 160,252,180,168,144,96,132,114,126,216,216,312,200,80,240,72,280,348,112

%N Number of integer solutions to a^2 + 2*b^2 + 2*c^2 + 2*d^2 = n.

%C a(n) > 0 for n >= 0.

%H Seiichi Manyama, <a href="/A320149/b320149.txt">Table of n, a(n) for n = 0..10000</a>

%F G.f.: theta_3(q) * theta_3(q^2)^3.

%Y Cf. A320150, A236924, A320151, A320152, A320153.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Oct 06 2018