%I #22 Aug 31 2024 08:31:00
%S 1,1,10,210,6840,303600,17100720,1168675200,93963542400,8691104822400,
%T 909171781056000,106137499051584000,13679492361575040000,
%U 1929327666754295808000,295570742023171270656000,48877281133334949335040000,8677556868736487617966080000
%N a(n) = (5*n)!/(4*n+1)!.
%F E.g.f.: exp( 1/5 * Sum_{k>=1} binomial(5*k,k) * x^k/k ). - _Seiichi Manyama_, Feb 08 2024
%F a(n) = A000142(n)*A002294(n). - _Alois P. Heinz_, Feb 08 2024
%F From _Seiichi Manyama_, Aug 31 2024: (Start)
%F E.g.f. satisfies A(x) = 1/(1 - x*A(x)^4).
%F a(n) = Sum_{k=0..n} (4*n+1)^(k-1) * |Stirling1(n,k)|. (End)
%o (PARI) a(n) = (5*n)!/(4*n+1)!;
%o (Python)
%o from sympy import ff
%o def A365341(n): return ff(5*n,n-1) # _Chai Wah Wu_, Sep 01 2023
%Y Cf. A001761, A001763, A052795, A365340.
%Y Cf. A004343.
%Y Cf. A000142, A002294.
%K nonn,easy
%O 0,3
%A _Seiichi Manyama_, Sep 01 2023