OFFSET
0,3
FORMULA
E.g.f. A(x) satisfies A(x) = sqrt( 1 + 2*x*A(x)*exp(x*A(x)) ).
a(n) = (n!/(n+1)) * Sum_{k=0..n} 2^k * k^(n-k) * binomial(n/2+1/2,k)/(n-k)!.
PROG
(PARI) a(n) = n!*sum(k=0, n, 2^k*k^(n-k)*binomial(n/2+1/2, k)/(n-k)!)/(n+1);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 11 2025
STATUS
approved