A320201 Number of integer solutions to a^2 + 2*b^2 + 4*c^2 + 13*d^2 = n.

1, 2, 2, 4, 4, 4, 8, 8, 6, 6, 8, 4, 8, 14, 4, 12, 20, 16, 18, 28, 24, 20, 36, 24, 16, 30, 32, 16, 32, 28, 16, 36, 30, 32, 32, 56, 28, 36, 52, 24, 56, 40, 24, 20, 40, 32, 32, 48, 40, 42, 50, 56, 42, 64, 52, 64, 48, 40, 80, 28, 60, 80, 52, 52, 44, 80, 40, 108, 88, 32, 100

Offset: 0

Author

Seiichi Manyama, Oct 07 2018

Keywords

• nonn

Comments

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

Links

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

Crossrefs

Cf. A320193, A320194, A320195, A320196, A033720, A320197, A320198, A320199, A320200, A320202.

Formula

G.f.: theta_3(q) * theta_3(q^2) * theta_3(q^4) * theta_3(q^13).