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%I #9 Mar 09 2018 17:21:35
%S 257,271,1201,10651,135391,316234143481,
%T 49988475139107080748861383849035044804037186461213252284425520655249250725695020643146597883951938106998443603515881
%N Primes of the form k!2+256, where k!2 is the double factorial number (A006852).
%C The next term has 174 digits. - _Harvey P. Dale_, Mar 09 2018
%H Robert Price, <a href="/A288411/b288411.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+256&action=Search">PRP Records.Search for n!2+256.</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] + 256, {i, 0, 100}], PrimeQ[#]&]
%t Select[Range[200]!!+256,PrimeQ] (* _Harvey P. Dale_, Mar 09 2018 *)
%Y Cf. A076195.
%K nonn
%O 1,1
%A _Robert Price_, Jun 08 2017