A368368 - OEIS

%I #14 Jan 29 2024 10:49:55

%S 0,9,1772,662544,458284375,543682781641,1033215730131200,

%T 2972173255049281536,12354182867688591966525,

%U 71417932095699615712890625,556289577698910589026958125056,5685963330436142993425055664640000,74579993174727714813743424870936891459

%N AGM transform of squares.

%C See A368366 for further information.

%H Paolo Xausa, <a href="/A368368/b368368.txt">Table of n, a(n) for n = 1..160</a>

%t A368368[n_] := (n*(n+1)*(2*n+1)/6)^n - n^n*n!^2;

%t Array[A368368, 15] (* _Paolo Xausa_, Jan 29 2024 *)

%o (Python)

%o from math import factorial

%o def A368368(n): return (n*(n+1)*((n<<1)+1)//6)**n-n**n*factorial(n)**2 # _Chai Wah Wu_, Jan 25 2024

%Y Cf. A368366.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, Jan 24 2024