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”).

A355253
Expansion of e.g.f. exp(2*(exp(x) - 1) - 3*x).
4
1, -1, 3, -5, 19, -29, 171, -69, 2339, 5139, 57563, 303403, 2397011, 17237507, 139011211, 1151110299, 10076637827, 91903924979, 874688607035, 8656097294091, 88932728790195, 946748093175523, 10426787247224043, 118620906668843131, 1392128306377939427, 16833088095308098003
OFFSET
0,3
COMMENTS
Inverse binomial transform of A194689.
LINKS
FORMULA
a(n) ~ 8 * n^(n-3) * exp(n/LambertW(n/2) - n - 2) / (sqrt(1 + LambertW(n/2)) * LambertW(n/2)^(n-3)).
a(0) = 1; a(n) = -3 * a(n-1) + 2 * Sum_{k=1..n} binomial(n-1,k-1) * a(n-k). - Ilya Gutkovskiy, Dec 04 2023
MATHEMATICA
nmax = 30; CoefficientList[Series[Exp[2*Exp[x]-2-3*x], {x, 0, nmax}], x] * Range[0, nmax]!
PROG
(PARI) my(x='x+O('x^30)); Vec(serlaplace(exp(2*(exp(x) - 1) - 3*x))) \\ Michel Marcus, Dec 04 2023
CROSSREFS
KEYWORD
sign
AUTHOR
Vaclav Kotesovec, Jun 26 2022
STATUS
approved