|
| |
|
|
A004421
|
|
Expansion of (Sum_{n=-inf..inf} x^(n^2))^(-20).
|
|
1
|
|
|
|
1, -40, 840, -12320, 141640, -1358448, 11297440, -83631680, 561539400, -3468363400, 19922193200, -107343635040, 546373245600, -2642351627440, 12200693947200, -54007656632000, 230002160331080, -945228781171920
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
0,2
|
|
|
LINKS
|
Seiichi Manyama, Table of n, a(n) for n = 0..10000
|
|
|
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 = 20 for this sequence. - Vaclav Kotesovec, Aug 18 2015
|
|
|
MATHEMATICA
|
nmax = 30; CoefficientList[Series[Product[((1 + (-x)^k)/(1 - (-x)^k))^20, {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Aug 18 2015 *)
nmax = 30; CoefficientList[Series[EllipticTheta[3, 0, x]^(-20), {x, 0, nmax}], x] (* Vaclav Kotesovec, Jun 24 2017 *)
|
|
|
CROSSREFS
|
Sequence in context: A162402 A010992 A250584 * A247411 A250986 A190825
Adjacent sequences: A004418 A004419 A004420 * A004422 A004423 A004424
|
|
|
KEYWORD
|
sign
|
|
|
AUTHOR
|
N. J. A. Sloane
|
|
|
STATUS
|
approved
|
| |
|
|
