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 A287956 #4 Jun 03 2017 15:26:11 %S A287956 1,5,7,11,13,17,37,43,55,107,139,149,157,211,223,343,373,409,523, %T A287956 12049,16457,17143,17543,18391,25829,25945,31307,34601,41687 %N A287956 Numbers k such that k!6 + 6 is prime, where k!6 is the sextuple factorial number (A085158 ). %C A287956 Corresponding primes are: 7, 11, 13, 61, 97, 941, 49579081, 2131900231, 5745471106381, ... %C A287956 a(43) > 50000. %C A287956 Terms > 35 correspond to probable primes. %H A287956 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n!6+6&action=Search">PRP Records. Search for n!6+6.</a> %H A287956 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 A287956 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a> %e A287956 11!6 + 6 = 11*5 + 6 = 61 is prime, so 11 is in the sequence. %t A287956 MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]]; %t A287956 Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 6] + 6] &] %Y A287956 Cf. A007661, A037082, A084438, A123910, A242994. %K A287956 nonn,more %O A287956 1,2 %A A287956 _Robert Price_, Jun 03 2017