OFFSET
1,2
COMMENTS
See A368366 for further information.
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..160
MATHEMATICA
A368368[n_] := (n*(n+1)*(2*n+1)/6)^n - n^n*n!^2;
Array[A368368, 15] (* Paolo Xausa, Jan 29 2024 *)
PROG
(Python)
from math import factorial
def A368368(n): return (n*(n+1)*((n<<1)+1)//6)**n-n**n*factorial(n)**2 # Chai Wah Wu, Jan 25 2024
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jan 24 2024
STATUS
approved