OFFSET
0,2
PROG
(PARI) {a(n)=local(L=matrix(n+1, n+1, r, c, if(r>=c, binomial(2*r-2, 2*c-1))), A);
A=sum(m=0, n, L^m/m!); sum(k=0, n, A[n+1, k+1])}
for(n=0, 25, print1(a(n), ", "))
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Aug 24 2014
STATUS
approved