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 A051399 #8 Nov 10 2023 12:27:30
%S A051399 0,1,2,5,31,745,89401,64368721,324418353841,13080548026869121,
%T A051399 4746669267990266628481,17224713439683079541431852801,
%U A051399 687555441429141549439426981886956801,329340156533265088807964627407023326809881601
%N A051399 a(n) = (n-1)!*a(n-1)+1.
%H A051399 Harvey P. Dale, <a href="/A051399/b051399.txt">Table of n, a(n) for n = 0..44</a>
%t A051399 nxt[{n_,a_}]:={n+1,n!*a+1}; NestList[nxt,{0,0},15][[All,2]] (* _Harvey P. Dale_, May 29 2017 *)
%K A051399 nonn
%O A051399 0,3
%A A051399 _Aleksandar Petojevic_