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A076188 Numbers k such that k!! + 2^3 is prime. 13

%I #22 May 28 2021 17:43:37

%S 3,5,7,9,15,17,25,41,63,79,91,103,299,341,431,445,465,519,1251,2469,

%T 2507,2549,6817,8519,18983,38715

%N Numbers k such that k!! + 2^3 is prime.

%C a(27) > 50000. - _Robert Price_, Jan 06 2015

%H Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=n%212%2B2%5E3">PRP Records.</a>

%H OpenPFGW Project, <a href="http://www.primeform.net/openpfgw/">Primality Tester</a>

%t lst={}; Do[If[PrimeQ[n!!+2^3], AppendTo[lst, n]], {n, 0, 50000}]; lst

%t Select[Range[40000],PrimeQ[#!!+8]&] (* _Harvey P. Dale_, May 28 2021 *)

%Y Cf. A006882, A080778 and A076185, A076186, A076189, A076190, A076193, A076194, A076195, A076196, A076197 for other values of s in n!!+2^s.

%K nonn,more

%O 1,1

%A _Zak Seidov_, Nov 02 2002

%E Edited and extended (n<4096) by _Hugo Pfoertner_, Jun 19 2003

%E More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008

%E a(25) from _Robert Price_, Nov 01 2012

%E a(26) from _Robert Price_, Jan 06 2015

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Last modified March 28 09:04 EDT 2024. Contains 371240 sequences. (Running on oeis4.)