A288878 - OEIS

A288878

Primes of the form k!3 + 3^2, where k!3 is the triple factorial number (A007661).

%I #5 Jun 18 2017 22:06:27

%S 11,13,19,37,89,12329,209449,1106569,24344329,96342409,2504902409,

%T 17961239296009,52580450364682240009,2295148179742698933452800009,

%U 7825229077844441903818866688000009,145302140752338100885902776123355299840000009

%N Primes of the form k!3 + 3^2, where k!3 is the triple factorial number (A007661).

%H Robert Price, <a href="/A288878/b288878.txt">Table of n, a(n) for n = 1..24</a>

%H Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n3+3^2&action=Search">PRP Records.Search for n!3+3^2.</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] + 3^2, {i, 0, 100}], PrimeQ[#]&]

%Y Cf. A247865.

%K nonn

%O 1,1

%A _Robert Price_, Jun 18 2017