OFFSET
0,9
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..583 (terms 0..250 from Alois P. Heinz)
E. A. Enneking and J. C. Ahuja, Generalized Bell numbers, Fib. Quart., 14 (1976), 67-73.
I. Mezo, Periodicity of the last digits of some combinatorial sequences, arXiv preprint arXiv:1308.1637 [math.CO], 2013 and J. Int. Seq. 17 (2014) #14.1.1.
FORMULA
E.g.f.: exp(exp(x)-1-x-x^2/2-x^3/6).
a(0) = 1; a(n) = Sum_{k=4..n} binomial(n-1,k-1) * a(n-k). - Ilya Gutkovskiy, Feb 09 2020
MAPLE
G:={P=Set(Set(Atom, card>=4))}:combstruct[gfsolve](G, unlabeled, x):seq(combstruct[count]([P, G, labeled], size=i), i=0..26); # Zerinvary Lajos, Dec 16 2007
MATHEMATICA
With[{nn=30}, CoefficientList[Series[Exp[Exp[x]-1-x-x^2/2-x^3/6], {x, 0, nn}], x]Range[0, nn]!] (* Harvey P. Dale, Jun 28 2012 *)
CROSSREFS
KEYWORD
easy,nice,nonn
AUTHOR
Steven C. Fairgrieve (fsteven(AT)math.wvu.edu), Nov 06 2000
EXTENSIONS
Corrected and extended by Christian G. Bower and James A. Sellers, Nov 09 2000
STATUS
approved