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 A256669 #22 Sep 08 2022 08:46:11
%S A256669 0,-1,-2,711,620448401733239439359972
%N A256669 a(n) = (n!)! - n! - n.
%C A256669 For n>0, a(n) is divisible by n. - _Michel Marcus_, Apr 08 2015
%e A256669 For n=3, a(3) = (3!)!-3!-3 = 6!-6-3 = 720-9 = 711.
%p A256669 A256669:=n->(n!)!-n!-n: seq(A256669(n), n=0..5); # _Wesley Ivan Hurt_, Apr 14 2015
%t A256669 Table[(n!)! - n! - n, {n, 5}] (* _Michael De Vlieger_, Apr 07 2015 *)
%o A256669 (Magma) [Factorial(Factorial(n))-Factorial(n)-n: n in [0..5]]; // _Vincenzo Librandi_, Apr 08 2015
%o A256669 (Sage) [factorial(factorial(n))-factorial(n)-n for n in [0..6]] # _Bruno Berselli_, Apr 08 2015
%Y A256669 Cf. A256509.
%K A256669 sign
%O A256669 0,3
%A A256669 _Assoul Abdelkarim_, Apr 07 2015