VOOZH about

URL: https://oeis.org/A371320

⇱ A371320 - OEIS

login
A371320
E.g.f. satisfies A(x) = exp(x) + x^2*A(x)^3.
1
1, 1, 3, 19, 181, 2341, 38071, 748567, 17262505, 457068745, 13667029291, 455560747291, 16750696633309, 673549397276653, 29403437531813983, 1384945157486054431, 70010050730247746641, 3780682522365453684625, 217218502250130209410387
OFFSET
0,3
FORMULA
a(n) = n! * Sum_{k=0..floor(n/2)} (2*k+1)^(n-2*k-1) * binomial(3*k,k)/(n-2*k)!.
PROG
(PARI) a(n) = n!*sum(k=0, n\2, (2*k+1)^(n-2*k-1)*binomial(3*k, k)/(n-2*k)!);
CROSSREFS
Sequence in context: A303064 A343672 A161630 * A121083 A343685 A213533
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Mar 18 2024
STATUS
approved