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”).

A004424
Expansion of (Sum_{n=-inf..inf} x^(n^2))^(-23).
1
1, -46, 1104, -18400, 239154, -2581152, 24056160, -198823040, 1485433104, -10177345486, 64663512288, -384402300960, 2153523131040, -11437761254432, 57880610587200, -280265903825280, 1303272560982834, -5838468742907712
OFFSET
0,2
LINKS
FORMULA
a(n) ~ (-1)^n * exp(Pi*sqrt(m*n)) * m^((m+1)/4) / (2^(3*(m+1)/2) * n^((m+3)/4)), set m = 23 for this sequence. - Vaclav Kotesovec, Aug 18 2015
MATHEMATICA
nmax = 30; CoefficientList[Series[Product[((1 + (-x)^k)/(1 - (-x)^k))^23, {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Aug 18 2015 *)
CROSSREFS
Sequence in context: A162186 A162452 A010998 * A361183 A258464 A320552
KEYWORD
sign
STATUS
approved