This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A368368 #14 Jan 29 2024 10:49:55 %S A368368 0,9,1772,662544,458284375,543682781641,1033215730131200, %T A368368 2972173255049281536,12354182867688591966525, %U A368368 71417932095699615712890625,556289577698910589026958125056,5685963330436142993425055664640000,74579993174727714813743424870936891459 %N A368368 AGM transform of squares. %C A368368 See A368366 for further information. %H A368368 Paolo Xausa, <a href="/A368368/b368368.txt">Table of n, a(n) for n = 1..160</a> %t A368368 A368368[n_] := (n*(n+1)*(2*n+1)/6)^n - n^n*n!^2; %t A368368 Array[A368368, 15] (* _Paolo Xausa_, Jan 29 2024 *) %o A368368 (Python) %o A368368 from math import factorial %o A368368 def A368368(n): return (n*(n+1)*((n<<1)+1)//6)**n-n**n*factorial(n)**2 # _Chai Wah Wu_, Jan 25 2024 %Y A368368 Cf. A368366. %K A368368 nonn %O A368368 1,2 %A A368368 _N. J. A. Sloane_, Jan 24 2024