A368368 AGM transform of squares.

0, 9, 1772, 662544, 458284375, 543682781641, 1033215730131200, 2972173255049281536, 12354182867688591966525, 71417932095699615712890625, 556289577698910589026958125056, 5685963330436142993425055664640000, 74579993174727714813743424870936891459

Offset: 1

Author

N. J. A. Sloane, Jan 24 2024

Keywords

• nonn

Comments

See A368366 for further information.

Links

• Paolo Xausa, Table of n, a(n) for n = 1..160

Crossrefs

Cf. A368366.

Programs

Mathematica

A368368[n_] := (n*(n+1)*(2*n+1)/6)^n - n^n*n!^2;
Array[A368368, 15] (* Paolo Xausa, Jan 29 2024 *)

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