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 A076197 Numbers k such that k!! + 2^10 is prime. 12
 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 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), A076196 (s=9). Sequence in context: A091154 A057424 A027152 * A002596 A098597 A097038 Adjacent sequences:  A076194 A076195 A076196 * A076198 A076199 A076200 KEYWORD nonn,more 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 approved

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Last modified November 26 20:36 EST 2021. Contains 349343 sequences. (Running on oeis4.)