OFFSET
0,3
FORMULA
E.g.f. A(x) satisfies A(x) = 1 + x*A(x)^2*exp(4*x*A(x)).
a(n) = (1/(n+1)) * Sum_{k=0..n} (4*k)^(n-k) * (n+k)!/(k! * (n-k)!).
PROG
(PARI) a(n) = sum(k=0, n, (4*k)^(n-k)*(n+k)!/(k!*(n-k)!))/(n+1);
CROSSREFS
KEYWORD
nonn,new
AUTHOR
Seiichi Manyama, Mar 13 2025
STATUS
approved