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 A288889 #7 Jul 28 2022 03:50:10
%S A288889 5,7,13,31,83,283,883,3643,12323,58243,1106563,4188803,2504902403,
%T A288889 17041024003,72642169603,2324549427203,126757680265216003,
%U A288889 38900816605808456499200003,26070192823309041523916800003,254451773522587035734629406212096000003
%N A288889 Primes of the form k!3+3, where k!3 is the triple factorial number (A007661).
%H A288889 Robert Price, <a href="/A288889/b288889.txt">Table of n, a(n) for n = 1..24</a>
%H A288889 Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3+3&action=Search">PRP Records.Search for n!3+3.</a>
%H A288889 Joe McLean, <a href="http://web.archive.org/web/20091027034731/http://uk.geocities.com/nassarawa%40btinternet.com/probprim2.htm">Interesting Sources of Probable Primes</a>
%H A288889 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%t A288889 MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t A288889 Select[Table[MultiFactorial[i, 3] + 3, {i, 0, 100}], PrimeQ[#]&]
%Y A288889 Cf. A007661, A249400.
%K A288889 nonn
%O A288889 1,1
%A A288889 _Robert Price_, Jun 18 2017