A028626 Expansion of (theta_3(z)*theta_3(15z) + theta_2(z)*theta_2(15z))^2.

1, 4, 4, 0, 12, 24, 8, 16, 36, 4, 64, 16, 16, 24, 48, 20, 60, 40, 4, 48, 152, 16, 80, 48, 24, 124, 88, 0, 112, 56, 68, 64, 116, 32, 104, 176, 12, 56, 112, 32, 336, 104, 48, 96, 176, 24, 144, 112, 64, 100, 364, 32, 200, 88, 8, 256, 240, 32, 184, 112, 156, 120, 192

Offset

0,2

Links

Jinyuan Wang, Table of n, a(n) for n = 0..1000

Prog

(PARI) a(n) = if( n<0, 0, polcoeff( (1 + 2 * x * Ser(qfrep( [ 2, 1; 1, 8], n, 1)))^2, n)); \\ Jinyuan Wang, Feb 19 2020

Crossrefs

Sequence in context: A199739 A121547 A377150 * A205507 A137862 A006805

Adjacent sequences: A028623 A028624 A028625 * A028627 A028628 A028629

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Jinyuan Wang, Feb 19 2020

Status

approved