OFFSET
0,4
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..442
FORMULA
E.g.f.: (1 - x)^(-(log(1 - x))^2).
a(0) = 1; a(n) = 6 * Sum_{k=1..n} binomial(n-1,k-1) * |Stirling1(k,3)| * a(n-k).
a(n) = Sum_{k=0..floor(n/3)} (3*k)! * |Stirling1(n,3*k)|/k!.
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp(-log(1-x)^3)))
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace((1-x)^(-log(1-x)^2)))
(PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=6*sum(j=1, i, binomial(i-1, j-1)*abs(stirling(j, 3, 1))*v[i-j+1])); v;
(PARI) a(n) = sum(k=0, n\3, (3*k)!*abs(stirling(n, 3*k, 1))/k!);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, May 06 2022
STATUS
approved