A334570 E.g.f.: exp(-(x + x^2/2 + x^3/3 + x^4/4)).
1, -1, 0, 0, 0, 24, -24, -120, -720, -5040, 32256, 169344, 743040, -380160, -91048320, -408710016, -174230784, 29842525440, 455765667840, 1061427732480, -18914141343744, -379628241094656, -3305984467691520, 10588546824468480, 458522651844956160, 5722461010387021824
Offset: 0
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..500
Programs
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Mathematica
m = 25; Range[0, m]! * CoefficientList[Series[Exp[-(x + x^2/2 + x^3/3 + x^4/4)], {x, 0, m}], x] (* Amiram Eldar, May 03 2021 *)
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PARI
N=40; x='x+O('x^N); Vec(serlaplace(exp(-x-x^2/2-x^3/3-x^4/4)))
Formula
a(0) = 1 and a(n) = - (n-1)! * Sum_{k=1..min(4,n)} a(n-k)/(n-k)!.