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”).

A307504
Expansion of Product_{k>=1} 1/(1-x^k)^((-1)^k*k^k).
2
1, -1, 4, -31, 293, -3499, 51284, -891276, 17928335, -409921846, 10500040633, -297796771914, 9262574642871, -313459274848233, 11464944476563718, -450647901022275715, 18943108018829605740, -847933752191806388254, 40266301788890216414608, -2021846883773977115156632
OFFSET
0,3
COMMENTS
This sequence is obtained from the generalized Euler transform in A266964 by taking f(n) = (-1)^n * n^n, g(n) = 1.
LINKS
FORMULA
a(n) ~ (-1)^n * n^n * (1 + exp(-1)/n + (exp(-1)/2 + 4*exp(-2))/n^2). - Vaclav Kotesovec, Apr 12 2019
MATHEMATICA
nmax=20; CoefficientList[Series[Product[1/(1-x^k)^((-1)^k*k^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Apr 12 2019 *)
PROG
(PARI) N=20; x='x+O('x^N); Vec(1/prod(k=1, N, (1-x^k)^((-1)^k*k^k)))
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 11 2019
STATUS
approved