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 A289823 #4 Jul 13 2017 21:27:37
%S A289823 51679,202879,4182239,608601439,2504895839,81359229945439,
%T A289823 664565853945439,262134882788466681439,
%U A289823 2103662445439858602854085842728187330559993439,17994728558292550488813850298696914425610239993439
%N A289823 Primes of the form k!3-6561, where k!3 is the triple factorial number (A007661).
%H A289823 Robert Price, <a href="/A289823/b289823.txt">Table of n, a(n) for n = 1..13</a>
%H A289823 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3-6561&action=Search">PRP Records.Search for n!3-6561.</a>
%H A289823 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 A289823 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%t A289823 MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t A289823 Select[Table[MultiFactorial[i, 3] - 6561, {i, 14, 100}], PrimeQ[#]&]
%Y A289823 Cf. A261344.
%K A289823 nonn
%O A289823 1,1
%A A289823 _Robert Price_, Jul 12 2017