|
%I #9 Mar 08 2020 19:23:14
%S 53,853,3613,24344293,72642169573,2576442067869429759973,
%T 38900816605808456499199973,26070192823309041523916799973,
%U 17978533302590087193373917833428087202627190783999999973
%N Primes of the form k!3-27, where k!3 is the triple factorial number (A007661).
%H Harvey P. Dale, <a href="/A289818/b289818.txt">Table of n, a(n) for n = 1..21</a>
%H Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3-27&action=Search">PRP Records.Search for n!3-27.</a>
%H 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 OpenPFGW Project, <a href="http://sourceforge.net/projects/openpfgw/">Primality Tester</a>
%t MultiFactorial[n_, k_] := If[n<1, 1, n*MultiFactorial[n-k, k]];
%t Select[Table[MultiFactorial[i, 3] - 27, {i, 7, 100}], PrimeQ[#]&]
%t Select[Table[Times@@Range[n,1,-3]-27,{n,7,150}],PrimeQ] (* _Harvey P. Dale_, Mar 08 2020 *)
%Y Cf. A247463.
%K nonn
%O 1,1
%A _Robert Price_, Jul 12 2017
|
