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 A085147 #17 May 31 2024 19:57:08 %S A085147 3,4,6,8,12,16,22,24,54,56,98,152,156,176,256,454,460,720,750,770,800, %T A085147 1442,2846,5920,7066,12778,19978,22726,25938,27780,36072,39746,48244 %N A085147 Numbers k such that k!!!! - 1 is prime. %C A085147 The search for multifactorial primes started by Ray Ballinger is now continued by a team of volunteers on the website of Ken Davis (see link). %H A085147 Ken Davis, <a href="http://mfprimes.free-dc.org">Status of Search for Multifactorial Primes</a>. %H A085147 Ken Davis, <a href="http://mfprimes.free-dc.org/mfdata/f04m.html">Results for n!4-1</a>. %t A085147 MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]]; %t A085147 Select[Range[0, 1000], PrimeQ[MultiFactorial[#, 4] - 1] & ] (* _Robert Price_, Apr 19 2019 *) %t A085147 Select[Range[48300],PrimeQ[Times@@Range[#,1,-4]-1]&] (* _Harvey P. Dale_, Aug 11 2020 *) %Y A085147 Cf. A007662 (quadruple factorials), A085146. %K A085147 hard,nonn %O A085147 1,1 %A A085147 _Hugo Pfoertner_, Jun 25 2003 %E A085147 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008