A079902 G.f. = { 1+sum(4*n*q^n, n=1..infinity)} / { theta series for square lattice }.

1, 0, 4, -4, 12, -20, 40, -68, 124, -208, 352, -580, 944, -1508, 2392, -3732, 5772, -8836, 13396, -20132, 30024, -44412, 65240, -95188, 137984, -198808, 284816, -405764, 575072, -810980, 1138184, -1590132, 2211868, -3063740, 4226640, -5808372, 7952204, -10848196, 14747560

Offset

0,3

Links

Table of n, a(n) for n=0..38.

Example

1 + 4*q + 8*q^2 + 12*q^3 + 16*q^4 + 20*q^5 + 24*q^6 + 28*q^7 + ... / 1 + 4*q + 4*q^2 + 4*q^4 + 8*q^5 + 4*q^8 + 4*q^9 + 8*q^10 + 8*q^13 + ... = 1 + 4*q^2 - 4*q^3 + 12*q^4 - 20*q^5 + 40*q^6 - 68*q^7 + 124*q^8 - 208*q^9 + ...

Crossrefs

Sequence in context: A053415 A303315 A331606 * A309128 A120033 A097073

Adjacent sequences: A079899 A079900 A079901 * A079903 A079904 A079905

Keyword

sign

Author

N. J. A. Sloane, Feb 21 2003

Status

approved