OFFSET
0,4
FORMULA
It follows that:
a(n)=((n-1)!*sum(i=0..n-1, (binomial(n,i)*sum(j=0..n, j!*(-1)^(j)*binomial(n,j)*stirling1(n-i-1,j)))/(n-i-1)!)), n>0, a(0)=1. [Vladimir Kruchinin, Oct 13 2012]
PROG
(Maxima)
a(n):=if n=0 then 1 else ((n-1)!*sum((binomial(n, i)*sum(j!*(-1)^(j)*binomial(n, j)*stirling1(n-i-1, j), j, 0, n))/(n-i-1)!, i, 0, n-1)); [Vladimir Kruchinin, Oct 13 2012]
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Jim Ferry (jferry(AT)alum.mit.edu), Mar 14 2003
EXTENSIONS
Entry revised by Vladimir Kruchinin, Oct 13 2012
Further edited by N. J. A. Sloane, Jan 19 2019 following advice from Gilbert Labelle.
STATUS
approved