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 A291347 #8 Sep 25 2019 14:53:58 %S A291347 3,9,15,17,19,29,31,45,55,63,73,101,135,173,217,271,439,535,729,787, %T A291347 933,1473,1651,6617,7805,12461,13253,18627,20243,55271 %N A291347 Numbers k such that k!4 + 2^6 is prime, where k!4 = k!!!! is the quadruple factorial number (A007662). %C A291347 Corresponding primes are: 67, 109, 3529, 10009, 65899, 151412689, 1267389649, ... %C A291347 a(31) > 10^5. %C A291347 Terms > 31 correspond to probable primes. %H A291347 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n%214%2B4&action=Search">PRP Records. Search for n!4+64.</a> %H A291347 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 A291347 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a> %e A291347 15!4 + 2^6 = 15*11*7*3*1 + 64 = 3529 is prime, so 15 is in the sequence. %t A291347 MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]]; %t A291347 Select[Range[0, 50000], PrimeQ[MultiFactorial[#, 4] + 2^6] &] %Y A291347 Cf. A007662, A037082, A084438, A123910, A242994. %K A291347 nonn,more %O A291347 1,1 %A A291347 _Robert Price_, Aug 22 2017 %E A291347 a(30) from _Robert Price_, Sep 25 2019