OFFSET
0,2
FORMULA
E.g.f. A(x) satisfies: A(exp(x) - 1) = 1 + 2*x*A(x).
a(0) = 1; a(n) = 2 * Sum_{k=1..n} k * Stirling1(n,k) * a(k-1).
PROG
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=2*sum(j=1, i, j*stirling(i, j, 1)*v[j])); v;
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Jun 19 2022
STATUS
approved