OFFSET
2,1
LINKS
Andrew Howroyd, Table of n, a(n) for n = 2..1276 (first 50 rows)
Philippe Flajolet and Robert Sedgewick, Analytic Combinatorics, Cambridge Univ. Press, 2009, page 179.
FORMULA
E.g.f.: x*exp(y * T(x)) where T(x) is the e.g.f. for A000169.
EXAMPLE
Triangle begins:
2;
6 3;
36 24 4;
320 240 60 5;
3750 3000 900 120 6;
54432 45360 15120 2520 210 7;
MATHEMATICA
nn=10; t=Sum[n^(n-1)x^n/n!, {n, 1, nn}]; f[list_]:=Select[list, #>0&]; Map[f, Drop[Transpose[Table[Range[0, nn]!CoefficientList[Series[x t^k/k!, {x, 0, nn}], x], {k, 1, 8}]], 2]]//Flatten
PROG
(PARI) T(n)={my(f=serreverse(x*exp(-x + O(x^n)))); [Vecrev(p/y) | p<-Vec(serlaplace(x*exp(y*f) - x))]}
{ my(A=T(7)); for(n=1, #A, print(A[n])) } \\ Andrew Howroyd, Jan 22 2020
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Geoffrey Critzer, Feb 07 2012
STATUS
approved