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Primes of the form k!2+2, where k!2 is the double factorial number (A006852).
1

%I #5 Jun 08 2017 18:19:24

%S 3,5,17,107,947,13749310577,316234143227,213458046676877,

%T 495179769008019818390136611716089140627,

%U 13114900840751548972796135496384318234575359262373046877,28352254429826839019508359891905756542124154226667992913078222750278633810791015627

%N Primes of the form k!2+2, where k!2 is the double factorial number (A006852).

%H Robert Price, <a href="/A288376/b288376.txt">Table of n, a(n) for n = 1..12</a>

%H Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n2+2&amp;action=Search">PRP Records.Search for n!2+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, 2] + 2, {i, 0, 100}], PrimeQ[#]&]

%Y Cf. A076815.

%K nonn

%O 1,1

%A _Robert Price_, Jun 08 2017