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 A275929 #17 Sep 08 2022 08:46:17
%S A275929 4,5,8,17,54,247,1448,10089,80650,725771,7257612,79833613,958003214,
%T A275929 12454041615,174356582416,2615348736017,41845579776018,
%U A275929 711374856192019,12804747411456020,243290200817664021,4865804016353280022,102181884343418880023,2248001455555215360024
%N A275929 a(n) = 2*(n-1)! + n + 1.
%H A275929 Vincenzo Librandi, <a href="/A275929/b275929.txt">Table of n, a(n) for n = 1..200</a>
%H A275929 R. C. Castillo, <a href="http://www.apjmr.com/wp-content/uploads/2015/10/APJMR-2015-3.4.2.15.pdf">On the Sum of Corresponding Factorials and Triangular Numbers: Runsums, Trapezoids and Politeness</a>, Asia Pacific Journal of Multidisciplinary Research, 3 (2015), 95-101.
%F A275929 E.g.f.: (1+x)*exp(x) - 2*log(1-x) - 1. - _Robert Israel_, Aug 30 2016
%p A275929 seq(2*(n-1)! + n + 1,n=1..30); # _Robert Israel_, Aug 30 2016
%t A275929 Table[2 (n - 1)! + n + 1, {n, 23}] (* _Michael De Vlieger_, Aug 30 2016 *)
%o A275929 (Magma) [2*Factorial(n-1) + n + 1: n in [1..30]]; // _Vincenzo Librandi_, Aug 31 2016
%K A275929 nonn
%O A275929 1,1
%A A275929 _N. J. A. Sloane_, Aug 30 2016