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 A173322 #21 Jan 31 2025 11:11:46
%S A173322 5,5,9,25,97,481,2881,20161,161281,1451521,14515201,159667201,
%T A173322 1916006401,24908083201,348713164801,5230697472001,83691159552001,
%U A173322 1422749712384001,25609494822912001,486580401635328001,9731608032706560001,204363768686837760001
%N A173322 a(n) = 4*n! + 1.
%H A173322 Vincenzo Librandi, <a href="/A173322/b173322.txt">Table of n, a(n) for n = 0..200</a>
%F A173322 a(0) = 5, a(n) = n*a(n-1)-n+1. - _Sergei N. Gladkovskii_, Jul 04 2012
%p A173322 a:= proc(n) if n=0 then 5 else a(n) := n*a(n-1)-n+1 fi end: seq (a(n), n=0..25); # _Sergei N. Gladkovskii_, Jul 04 2012
%t A173322 4*Range[0,20]!+1 (* _Harvey P. Dale_, Jun 26 2012 *)
%t A173322 Table[4 n! + 1, {n, 0, 21}] (* _Vincenzo Librandi_, Sep 29 2013 *)
%o A173322 (Magma) [4*Factorial(n) + 1: n in [0..25]]; // _Vincenzo Librandi_, Sep 29 2013
%o A173322 (Magma) [5] cat [n eq 1 select n+4 else n*Self(n-1)-n+1: n in [1..25] ]; // _Vincenzo Librandi_, Sep 29 2013
%Y A173322 Cf. sequences of the type k*n!+1: A038507 (k=1), A052898 (k=2), A173324 (k=3), this sequence, A173319 (k=5), A173314 (k=6).
%K A173322 nonn,easy
%O A173322 0,1
%A A173322 _Vincenzo Librandi_, Feb 16 2010