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 A069152 #7 Jan 20 2024 18:49:43
%S A069152 0,1,2,23,84,719,4976,40311,362780,3628799,39896064,479001599,
%T A069152 6227020604,87178290975,1307674363904,20922789887999,355687427991024,
%U A069152 6402373705727999,121645100408672000,2432902008176639559
%N A069152 a(n) = (n-1)!-n^tau(n)/n^2.
%C A069152 n and a(n) have the same parity.
%t A069152 Table[(n - 1)! - n^DivisorSigma[0, n]/n^2, {n, 2, 25}] (* _Wesley Ivan Hurt_, Jan 20 2024 *)
%Y A069152 Cf. A062758.
%K A069152 easy,nonn
%O A069152 2,3
%A A069152 _Benoit Cloitre_, Apr 08 2002