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Primes of the form k!2+128, where k!2 is the double factorial number (A006852).
1

%I #9 Apr 09 2020 19:36:08

%S 131,233,34459553,654729203,191898783962510753,

%T 563862029680583509947947003,2980227913743310874726229193922003

%N Primes of the form k!2+128, where k!2 is the double factorial number (A006852).

%C The next term (a(8)) has 147 digits. - _Harvey P. Dale_, Apr 09 2020

%H Robert Price, <a href="/A288410/b288410.txt">Table of n, a(n) for n = 1..8</a>

%H Henri& Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n2+128&amp;action=Search">PRP Records.Search for n!2+128.</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] + 128, {i, 0, 100}], PrimeQ[#]&]

%t Select[Range[100]!!+128,PrimeQ] (* _Harvey P. Dale_, Apr 09 2020 *)

%Y Cf. A076194.

%K nonn

%O 1,1

%A _Robert Price_, Jun 08 2017