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A289700 Numbers k such that k!6 - 36 is prime, where k!6 is the sextuple factorial number (A085158).

%I A289700 #16 Nov 29 2018 04:05:01
%S A289700 11,19,25,55,61,113,131,133,439,529,1079,1621,2609,2825,3997,4235,
%T A289700 5081,7319,8365,9023,10273,18095,18199,22625,24535,27229,28883,99877
%N A289700 Numbers k such that k!6 - 36 is prime, where k!6 is the sextuple factorial number (A085158).
%C A289700 Corresponding primes are: 19, 1693, 43189, 5745471106339, 350473737488839, ...
%C A289700 a(29) > 10^5.
%C A289700 Terms > 25 correspond to probable primes.
%H A289700 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n!6-36&amp;action=Search">PRP Records. Search for n!6-36.</a>
%H A289700 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 A289700 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%e A289700 19!6 - 36 = 19*13*7*1 - 36 = 1693 is prime, so 19 is in the sequence.
%t A289700 MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
%t A289700 Select[Range[10, 50000], PrimeQ[MultiFactorial[#, 6] - 36] &]
%Y A289700 Cf. A007661, A037082, A084438, A085158, A123910, A242994.
%K A289700 nonn,more
%O A289700 1,1
%A A289700 _Robert Price_, Jul 09 2017
%E A289700 a(28) from _Robert Price_, Nov 28 2018