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 A289819 #22 Jul 31 2025 08:41:58
%S A289819 199,3559,12239,209359,4188719,2504902319,72642169519,528271743919,
%T A289819 2324549427119,13106744139423334399919,2295148179742698933452799919,
%U A289819 254451773522587035734629406212095999919,281238294844900882734503454910185471999919
%N A289819 Primes of the form k!3-81, where k!3 is the triple factorial number (A007661).
%H A289819 Harvey P. Dale, <a href="/A289819/b289819.txt">Table of n, a(n) for n = 1..32</a> (first 19 terms from Robert Price)
%H A289819 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=k%213-81&action=Search">PRP Records. Search for k!3-81</a>.
%H A289819 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 A289819 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>.
%t A289819 MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t A289819 Select[Table[MultiFactorial[i, 3] - 81, {i, 9, 100}], PrimeQ[#]&]
%t A289819 Select[Table[Times@@Range[n,1,-3],{n,8,150}]-81,PrimeQ] (* _Harvey P. Dale_, Nov 14 2022 *)
%Y A289819 Cf. A247464.
%K A289819 nonn
%O A289819 1,1
%A A289819 _Robert Price_, Jul 12 2017