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A076188
Numbers k such that k!! + 2^3 is prime.
13
3, 5, 7, 9, 15, 17, 25, 41, 63, 79, 91, 103, 299, 341, 431, 445, 465, 519, 1251, 2469, 2507, 2549, 6817, 8519, 18983, 38715
OFFSET
1,1
COMMENTS
a(27) > 50000. - Robert Price, Jan 06 2015
LINKS
Henri & Renaud Lifchitz, PRP Records.
OpenPFGW Project, Primality Tester
MATHEMATICA
lst={}; Do[If[PrimeQ[n!!+2^3], AppendTo[lst, n]], {n, 0, 50000}]; lst
Select[Range[40000], PrimeQ[#!!+8]&] (* Harvey P. Dale, May 28 2021 *)
CROSSREFS
Cf. A006882, A080778 and A076185, A076186, A076189, A076190, A076193, A076194, A076195, A076196, A076197 for other values of s in n!!+2^s.
Sequence in context: A329419 A235264 A064896 * A265852 A335132 A343727
KEYWORD
nonn,more
AUTHOR
Zak Seidov, Nov 02 2002
EXTENSIONS
Edited and extended (n<4096) by Hugo Pfoertner, Jun 19 2003
More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008
a(25) from Robert Price, Nov 01 2012
a(26) from Robert Price, Jan 06 2015
STATUS
approved