Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #5 Jun 13 2017 23:02:22
%S 2,3,5,7,37,67,313,751,2857,129169,576577,17873857,54286849,393750001,
%T 643458817,19053977918977,206180145819649,
%U 11716249122484566383298871297,177636555893291390456871518209,49055724379818682505120501943238657
%N Primes of the form k!5+1, where k!5 is the quintuple factorial number (A085157).
%H Robert Price, <a href="/A288718/b288718.txt">Table of n, a(n) for n = 1..28</a>
%H Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n5+1&action=Search">PRP Records.Search for n!5+1.</a>
%H 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 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%t MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t Select[Table[MultiFactorial[i, 5] + 1, {i, 0, 100}], PrimeQ[#]&]
%Y Cf. A085148.
%K nonn
%O 1,1
%A _Robert Price_, Jun 13 2017