OFFSET
0,3
COMMENTS
a(n) is the total number of cycles obtained by permuting the elements in every subset of {1,2,...,n}. - Geoffrey Critzer, Sep 24 2013
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..450
FORMULA
Binomial transform of A000254.
a(n) ~ n! * exp(1) * (log(n) + gamma), where gamma is the Euler-Mascheroni constant A001620. - Vaclav Kotesovec, Jul 02 2015
MAPLE
b:= proc(n) option remember; `if`(n<2, n, n*b(n-1)+(n-1)!) end:
a:= proc(n) add(b(k)*binomial(n, k), k=0..n) end:
seq(a(n), n=0..25); # Alois P. Heinz, Mar 07 2018
MATHEMATICA
nn=19; Range[0, nn]!CoefficientList[Series[Exp[x]Log[1/(1-x)]/(1-x), {x, 0, nn}], x] (* Geoffrey Critzer, Sep 24 2013 *)
PROG
(PARI) x='x+O('x^30); concat([0], Vec(serlaplace(exp(x)*log(1-x)/(x-1)))) \\ G. C. Greubel, Aug 28 2018
(Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(Exp(x)*Log(1-x)/(x-1))); [0] cat [Factorial(n)*b[n]: n in [1..m-1]]; // G. C. Greubel, Aug 28 2018
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Aug 28 2002
STATUS
approved