A320193 Number of integer solutions to a^2 + 2*b^2 + 4*c^2 + 4*d^2 = n.

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, 42, 72, 40, 48, 56, 16, 64, 62, 40, 36, 64, 42, 72, 108, 48, 72, 84, 96, 84, 100, 56, 48, 96, 68, 114, 42, 72, 120, 104, 120, 80, 112, 72, 168, 116, 48, 120, 64, 112, 126, 96

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)^2.

Crossrefs

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

Sequence in context: A147982 A329899 A051466 * A260215 A261156 A080015

Adjacent sequences: A320190 A320191 A320192 * A320194 A320195 A320196

Keyword

nonn

Author

Seiichi Manyama, Oct 07 2018

Status

approved