login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A320195
Number of integer solutions to a^2 + 2*b^2 + 4*c^2 + 6*d^2 = n.
11
1, 2, 2, 4, 4, 4, 10, 12, 10, 14, 16, 12, 24, 28, 12, 20, 28, 16, 26, 36, 8, 24, 48, 24, 30, 42, 28, 40, 72, 28, 32, 60, 34, 60, 64, 24, 28, 76, 36, 56, 80, 40, 60, 84, 72, 52, 96, 48, 72, 86, 42, 80, 56, 52, 82, 96, 36, 72, 112, 60, 120, 124, 60, 84, 124, 56, 96, 132, 32
OFFSET
0,2
COMMENTS
a(n) > 0 for n >= 0.
LINKS
FORMULA
G.f.: theta_3(q) * theta_3(q^2) * theta_3(q^4) * theta_3(q^6).
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 07 2018
STATUS
approved