A376873 a(n) = n! * |Stirling1(2*n, n)|.

1, 1, 22, 1350, 162456, 32319000, 9604465200, 3986353491120, 2202727143576960, 1563325251963995520, 1385918755006365216000, 1500893038955163069216000, 1949720475921117012670233600, 2992360962617823634351113600000, 5356716752093284789859604692736000

Offset: 0

Author

Peter Luschny, Oct 29 2024

Keywords

• nonn

Crossrefs

Cf. A132393, A187646, A225479.

Programs

Maple

a := n -> n! * abs(Stirling1(2*n, n)):
seq(a(n), n = 0..14);

Mathematica

Array[#!*Abs[StirlingS1[2 #, #]] &, 14] (* Michael De Vlieger, Oct 29 2024 *)

PARI

a(n) = n!*abs(stirling(2*n, n, 1)); \\ Michel Marcus, Oct 29 2024

Python

from sympy.functions.combinatorial.numbers import factorial, stirling
def A376873(n): return factorial(n)*stirling(n<<1,n,kind=1) # Chai Wah Wu, Oct 29 2024

Formula

a(n) = n!*A187646(n).

a(n) = A225479(2*n, n).