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 A005008 #23 Sep 08 2022 08:44:33
%S A005008 1,0,-2,-3,8,95,684,4991,40256,362799,3628700,39916679,479001456,
%T A005008 6227020631,87178291004,1307674367775,20922789887744,355687428095711,
%U A005008 6402373705727676,121645100408831639,2432902008176639600,51090942171709439559,1124000727777607679516
%N A005008 a(n) = n! - n^2.
%H A005008 Vincenzo Librandi, <a href="/A005008/b005008.txt">Table of n, a(n) for n = 0..400</a>
%H A005008 <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>
%F A005008 E.g.f.: 1/(1 - x) - x*(1 + x)*exp(x). - _Ilya Gutkovskiy_, Jan 27 2017
%t A005008 Table[n! - n^2, {n, 0, 30}] (* _Vladimir Joseph Stephan Orlovsky_, Jun 27 2011 *)
%o A005008 (Magma) [Factorial(n) - n^2: n in [0..25]]; // _Vincenzo Librandi_, Jun 28 2011
%o A005008 (PARI) a(n)=n!-n^2 \\ _Charles R Greathouse IV_, Jun 28 2011
%Y A005008 Cf. A000142, A000290.
%K A005008 sign,easy
%O A005008 0,3
%A A005008 _N. J. A. Sloane_