login
Number of integer solutions to a^2 + 2*b^2 + 4*c^2 + 4*d^2 = n.
11

%I #12 Oct 08 2018 04:13:18

%S 1,2,2,4,6,8,12,16,14,14,24,20,20,24,16,16,30,36,14,36,40,32,60,48,36,

%T 42,72,40,48,56,16,64,62,40,36,64,42,72,108,48,72,84,96,84,100,56,48,

%U 96,68,114,42,72,120,104,120,80,112,72,168,116,48,120,64,112,126,96

%N Number of integer solutions to a^2 + 2*b^2 + 4*c^2 + 4*d^2 = n.

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

%H Seiichi Manyama, <a href="/A320193/b320193.txt">Table of n, a(n) for n = 0..10000</a>

%F G.f.: theta_3(q) * theta_3(q^2) * theta_3(q^4)^2.

%Y Cf. A320194, A320195, A320196, A033720, A320197, A320198, A320199, A320200, A320201, A320202.

%K nonn

%O 0,2

%A _Seiichi Manyama_, Oct 07 2018