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 A289560 #87 Nov 04 2024 16:26:44
%S A289560 257,277,487,1267389841,50491808745015763381,
%T A289560 1008407509171875041482378381,429215532868726286171043772444743140881,
%U A289560 4551830726072842264843919206776501006328381
%N A289560 Primes of the form k!4+256, where k!4 is the quadruple factorial number (A007662).
%H A289560 Harvey P. Dale, <a href="/A289560/b289560.txt">Table of n, a(n) for n = 1..17</a>
%H A289560 Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n4+256&action=Search">PRP Records.Search for n!4+256.</a>
%H A289560 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 A289560 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%t A289560 MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t A289560 Select[Table[MultiFactorial[i, 4] + 256, {i, 0, 100}], PrimeQ[#]&]
%t A289560 Select[Table[256+Times@@Range[n,1,-4],{n,200}],PrimeQ] (* _Harvey P. Dale_, Nov 04 2024 *)
%Y A289560 Cf. A291349.
%K A289560 nonn
%O A289560 1,1
%A A289560 _Robert Price_, Sep 02 2017