OFFSET
0,3
FORMULA
E.g.f.: exp( 1/5 * Sum_{k>=1} binomial(5*k,k) * x^k/k ). - Seiichi Manyama, Feb 08 2024
From Seiichi Manyama, Aug 31 2024: (Start)
E.g.f. satisfies A(x) = 1/(1 - x*A(x)^4).
a(n) = Sum_{k=0..n} (4*n+1)^(k-1) * |Stirling1(n,k)|. (End)
PROG
(PARI) a(n) = (5*n)!/(4*n+1)!;
(Python)
from sympy import ff
def A365341(n): return ff(5*n, n-1) # Chai Wah Wu, Sep 01 2023
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Sep 01 2023
STATUS
approved