A320148 Number of integer solutions to a^2 + b^2 + 3*c^2 + 6*d^2 = n.

1, 4, 4, 2, 12, 16, 2, 16, 28, 8, 32, 40, 10, 48, 48, 8, 44, 40, 24, 72, 48, 16, 72, 64, 10, 52, 80, 38, 96, 112, 8, 80, 108, 12, 104, 128, 48, 144, 136, 8, 112, 104, 32, 168, 136, 64, 128, 96, 26, 132, 116, 36, 176, 208, 70, 96, 192, 28, 192, 232, 24, 240, 176, 80

Offset: 0

Author

Seiichi Manyama, Oct 06 2018

Keywords

• nonn

Comments

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

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A034896, A272364, A320147.

Formula

G.f.: theta_3(q)^2 * theta_3(q^3) * theta_3(q^6).