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Primes of the form k!3-6561, where k!3 is the triple factorial number (A007661).
1

%I #4 Jul 13 2017 21:27:37

%S 51679,202879,4182239,608601439,2504895839,81359229945439,

%T 664565853945439,262134882788466681439,

%U 2103662445439858602854085842728187330559993439,17994728558292550488813850298696914425610239993439

%N Primes of the form k!3-6561, where k!3 is the triple factorial number (A007661).

%H Robert Price, <a href="/A289823/b289823.txt">Table of n, a(n) for n = 1..13</a>

%H Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3-6561&amp;action=Search">PRP Records.Search for n!3-6561.</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] - 6561, {i, 14, 100}], PrimeQ[#]&]

%Y Cf. A261344.

%K nonn

%O 1,1

%A _Robert Price_, Jul 12 2017