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 A173317 #18 Dec 04 2024 09:13:15
%S A173317 4,4,9,29,119,599,3599,25199,201599,1814399,18143999,199583999,
%T A173317 2395007999,31135103999,435891455999,6538371839999,104613949439999,
%U A173317 1778437140479999,32011868528639999,608225502044159999
%N A173317 a(n) = 5*n! - 1.
%H A173317 Vincenzo Librandi, <a href="/A173317/b173317.txt">Table of n, a(n) for n = 0..200</a>
%F A173317 a(n) = 5*A000142(n)-1.
%F A173317 a(0)=4, a(n) = n*a(n-1)+n-1. - _Vincenzo Librandi_, Sep 30 2013
%t A173317 Table[5 n! - 1, {n, 0, 25}] (* _Vincenzo Librandi_, Sep 30 2013 *)
%o A173317 (Magma) [5*Factorial(n)-1: n in [0..25]]; // _Vincenzo Librandi_, Sep 30 2013
%o A173317 (Magma) [4] cat [n eq 1 select n+3 else n*Self(n-1)+n-1: n in [1..25] ]; // _Vincenzo Librandi_, Sep 30 2013
%Y A173317 Cf. sequences of the type k*n!-1: A033312 (k=1), A020543 (k=2), A173323 (k=3), A173321 (k=4), this sequence, A173316 (k=6).
%K A173317 nonn,easy
%O A173317 0,1
%A A173317 _Vincenzo Librandi_, Feb 16 2010
%E A173317 a(16) corrected from _Vincenzo Librandi_, Sep 30 2013