cp's OEIS Frontend

A289699 Numbers k such that k!6 - 32 is prime, where k!6 is the sextuple factorial number (A085158).

%I A289699 #14 Nov 29 2018 16:21:28
%S A289699 11,13,15,19,33,35,39,59,63,75,105,143,187,213,271,307,431,549,1211,
%T A289699 1597,1879,2025,3085,5995,5997,6697,6795,10543,21515,25811,34345,
%U A289699 57561,70797,71671
%N A289699 Numbers k such that k!6 - 32 is prime, where k!6 is the sextuple factorial number (A085158).
%C A289699 Corresponding primes are: 23, 59, 373, 1697, 7577923, 21827543, 295540213, ...
%C A289699 a(35) > 10^5.
%C A289699 Terms > 39 correspond to probable primes.
%H A289699 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n!6-32&amp;action=Search">PRP Records. Search for n!6-32.</a>
%H A289699 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 A289699 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%e A289699 15!6 - 32 = 15*9*3 - 32 = 373 is prime, so 15 is in the sequence.
%t A289699 MultiFactorial[n_, k_] := If[n < 1, 1, n*MultiFactorial[n - k, k]];
%t A289699 Select[Range[10, 50000], PrimeQ[MultiFactorial[#, 6] - 32] &]
%Y A289699 Cf. A007661, A037082, A084438, A123910, A242994.
%K A289699 nonn,more
%O A289699 1,1
%A A289699 _Robert Price_, Jul 09 2017
%E A289699 a(32)-a(34) from _Robert Price_, Aug 04 2018