The On-Line Encyclopedia of Integer Sequences (OEIS)

A076197 revision #27

A076197

Numbers n such that n!! + 2^10 is prime.

5, 7, 21, 33, 153, 167, 171, 391, 789, 1323, 2645, 8655, 10153, 39967, 45369, 47599

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(17) > 50000. - Robert Price, Feb 24 2015

LINKS

Henri & Renaud Lifchitz, PRP Records.

OpenPFGW Project, Primality Tester

MATHEMATICA

lst={}; Do[If[PrimeQ[n!!+2^10], (*Print[n]; *)AppendTo[lst, n]], {n, 6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Aug 26 2008 *)

PROG

(Python)

from gmpy2 import is_prime

A076197_list, g, h = [], 1, 1024

for i in range(3, 10**5, 2):

....g *= i

....if is_prime(g+h):

........A076197_list.append(i) # Chai Wah Wu, May 31 2015

CROSSREFS

Numbers n such n!! + 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), A076196 (s=9).

KEYWORD

nonn,more,changed

AUTHOR

Zak Seidov, Nov 02 2002

EXTENSIONS

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

8655 from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008

a(13) from Robert Price, Mar 10 2013

a(14)-a(16) from Robert Price, Feb 24 2015

STATUS

editing