OFFSET
0,4
FORMULA
a(n) = - n! * Sum_{k=0..n} (-3)^k * binomial((n-k)/3,k)/(n-k)!.
MATHEMATICA
With[{nn=20}, CoefficientList[Series[-Exp[x*CubeRoot[1-3x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Mar 18 2025 *)
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(-exp(x*(1-3*x)^(1/3))))
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Seiichi Manyama, Apr 10 2023
STATUS
approved
