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A320239
Expansion of theta_3(q) * theta_3(q^3) * theta_3(q^5), where theta_3() is the Jacobi theta function.
2
1, 2, 0, 2, 6, 2, 4, 4, 4, 14, 0, 0, 14, 4, 4, 0, 6, 12, 8, 4, 2, 20, 0, 4, 20, 2, 8, 10, 12, 4, 4, 4, 16, 32, 0, 0, 26, 4, 0, 12, 0, 20, 8, 4, 8, 6, 4, 4, 42, 18, 0, 8, 20, 12, 16, 0, 12, 48, 8, 8, 0, 16, 8, 12, 14, 0, 16, 4, 20, 24, 4, 0, 36, 28, 0, 2, 20, 8, 8, 4, 6
OFFSET
0,2
COMMENTS
Also the number of integer solutions (a_1, a_2, a_3) to the equation a_1^2 + 3*a_2^2 + 5*a_3^2 = n.
LINKS
Eric Weisstein's World of Mathematics, Jacobi Theta Functions
CROSSREFS
Product_{k=1..m} theta_3(q^(2*k-1)): A000122 (m=1), A033716 (m=2), this sequence (m=3), A320240 (m=4).
Cf. A320078.
Sequence in context: A306079 A373167 A242860 * A033727 A033757 A320240
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 08 2018
STATUS
approved