OFFSET
0,3
COMMENTS
Conjecturally, the sum of the permanents of all nXn 0-1 matrices.
LINKS
Michael De Vlieger, Table of n, a(n) for n = 0..55
MAPLE
a:= n-> n!*2^(n^2-n):
seq(a(n), n=0..14); # Alois P. Heinz, Oct 07 2024
MATHEMATICA
Array[#!*4^Binomial[#, 2] &, 12, 0] (* Michael De Vlieger, Oct 07 2024 *)
PROG
(PARI) a(n)=n!*4^binomial(n, 2)
(Python)
from sympy import factorial
def A376868(n): return factorial(n)<<n*(n-1) # Chai Wah Wu, Oct 07 2024
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Charles R Greathouse IV, Oct 07 2024
STATUS
approved