OFFSET
1,4
FORMULA
a(n) = numerator of A231530(n)/n!. - Chai Wah Wu, Feb 22 2024
EXAMPLE
PROG
(PARI) a370551(n) = numerator(real(prod(k=1, n, 1+I/k)))
(Python)
from math import factorial, gcd
from sympy.functions.combinatorial.numbers import stirling
def A370551(n): return (a:=sum(stirling(n+1, (k<<1)+1, kind=1)*(-1 if k&1 else 1) for k in range((n>>1)+1)))//gcd(a, factorial(n)) # Chai Wah Wu, Feb 22 2024
CROSSREFS
KEYWORD
sign,frac,easy
AUTHOR
Hugo Pfoertner, Feb 22 2024
STATUS
approved