A076196 Numbers k such that k!! + 2^9 is prime.

7, 13, 15, 19, 25, 133, 135, 199, 223, 297, 299, 511, 15263, 16491, 18967, 32455

Offset: 1

Author

Zak Seidov, Nov 02 2002

Keywords

• nonn
• more

Comments

a(17) > 50000. - Robert Price, Feb 15 2015

Links

• The OpenPFGW Project, Primality Tester

Crossrefs

Cf. A006882.

Numbers k such that k!! + 2^s is prime: A080778 (s=0), A076185 (s=1), A076186 (s=2), A076188 (s=3), A076189 (s=4), A076190 (s=5), A076193 (s=6), A076194 (s=7), A076195 (s=8), A076197 (s=10).

Programs

Mathematica

lst={};Do[If[PrimeQ[n!!+2^9], (*Print[n];*)AppendTo[lst, n]], {n, 6!}];lst (* Vladimir Joseph Stephan Orlovsky, Aug 26 2008 *)
Select[Range[33000],PrimeQ[#!!+2^9]&] (* Harvey P. Dale, Mar 29 2019 *)

Extensions

Edited and extended (n < 4096) by Hugo Pfoertner, Jun 19 2003

a(13)-a(15) from Robert Price, Feb 25 2013

a(16) from Robert Price, Feb 15 2015