A320153 - OEIS

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A320153

Number of integer solutions to a^2 + 2*b^2 + 2*c^2 + 7*d^2 = n.

7

1, 2, 4, 8, 6, 8, 8, 2, 16, 18, 24, 36, 24, 24, 16, 24, 26, 32, 60, 40, 40, 48, 8, 12, 56, 34, 72, 80, 34, 44, 24, 64, 44, 80, 96, 48, 102, 60, 40, 72, 72, 80, 144, 84, 52, 104, 40, 96, 120, 82, 92, 96, 120, 76, 80, 80, 84, 120, 136, 120, 72, 120, 64, 194, 102

(list; graph; refs; listen; history; text; internal format)

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)^2 * theta_3(q^7).

CROSSREFS

Cf. A320149, A320150, A236924, A320151, A320152.

Sequence in context: A212885 A319078 A246631 * A138284 A175156 A320152

Adjacent sequences: A320150 A320151 A320152 * A320154 A320155 A320156

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Oct 06 2018

STATUS

approved