A320197 Number of integer solutions to a^2 + 2*b^2 + 4*c^2 + 9*d^2 = n.

1, 2, 2, 4, 4, 4, 8, 8, 6, 8, 12, 8, 16, 20, 8, 24, 28, 20, 22, 28, 16, 24, 48, 8, 24, 38, 24, 36, 40, 20, 16, 64, 22, 32, 44, 24, 46, 56, 36, 16, 64, 28, 64, 68, 36, 56, 56, 72, 56, 90, 26, 56, 88, 44, 92, 48, 48, 80, 108, 48, 48, 96, 40, 120, 92, 16, 48, 108, 52

Offset

0,2

Comments

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

Links

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

Formula

G.f.: theta_3(q) * theta_3(q^2) * theta_3(q^4) * theta_3(q^9).

Crossrefs

Cf. A320193, A320194, A320195, A320196, A033720, A320198, A320199, A320200, A320201, A320202.

Sequence in context: A320199 A033756 A320198 * A124340 A071165 A137688

Adjacent sequences: A320194 A320195 A320196 * A320198 A320199 A320200

Keyword

nonn

Author

Seiichi Manyama, Oct 07 2018

Status

approved