OFFSET
1,2
COMMENTS
As the definition says, this entry deliberately omits the zero-th term 1. - N. J. A. Sloane, Jun 16 2021
REFERENCES
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
FORMULA
G.f. A(x) satisfies: A(x) = x - Sum_{k>=2} Bell(k) * A(x)^k. - Ilya Gutkovskiy, Apr 22 2020
MAPLE
read transforms; A := series(exp(exp(x)-1), x, 60); SERIESTOLISTMULT(%); subsop(1=NULL, %); REVERT(%);
# Alternative, using function CompInv from A357588:
CompInv(26, n -> combinat:-bell(n)); # Peter Luschny, Oct 05 2022
PROG
(PARI) a(n)=if(n<1, 0, polcoeff(serreverse(-1+serlaplace(exp(exp(x+x*O(x^n))-1))), n))
CROSSREFS
KEYWORD
sign
AUTHOR
EXTENSIONS
Signs corrected Dec 24 2001
STATUS
approved