A320149 Number of integer solutions to a^2 + 2*b^2 + 2*c^2 + 2*d^2 = n.

1, 2, 6, 12, 14, 24, 20, 16, 30, 14, 40, 60, 36, 72, 48, 16, 62, 36, 42, 108, 72, 96, 100, 48, 68, 42, 120, 120, 112, 168, 48, 64, 126, 40, 108, 192, 98, 216, 180, 48, 136, 84, 160, 252, 180, 168, 144, 96, 132, 114, 126, 216, 216, 312, 200, 80, 240, 72, 280, 348, 112

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. A320150, A236924, A320151, A320152, A320153.

Formula

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