This site is supported by donations to The OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A032471 Numbers k such that 189*2^k+1 is prime. 0
 1, 2, 6, 9, 17, 39, 45, 95, 359, 526, 609, 783, 818, 917, 1445, 1590, 1606, 1861, 2037, 3538, 3730, 6186, 7482, 11801, 12162, 23838, 25785, 27565, 30666, 37033, 37518, 52082, 74127, 90061, 133599, 219966, 238202, 241297, 280502, 632049, 724746, 845142, 943329, 1014433, 1115090 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Ray Ballinger, Proth Search Page Ray Ballinger and Wilfrid Keller, List of primes k.2^n + 1 for k < 300 Wilfrid Keller, List of primes k.2^n - 1 for k < 300 MAPLE select(k->isprime(189*2^k+1), [\$0..1000]); # Muniru A Asiru, Dec 18 2018 MATHEMATICA Select[Range[1000], PrimeQ[189*2^# + 1] & ] (* Robert Price, Dec 18 2018 *) PROG (PARI) is(n)=ispseudoprime(189*2^n+1) \\ Charles R Greathouse IV, Jun 13 2017 CROSSREFS Sequence in context: A257083 A054974 A072481 * A156222 A002886 A028724 Adjacent sequences:  A032468 A032469 A032470 * A032472 A032473 A032474 KEYWORD nonn,hard AUTHOR EXTENSIONS a(35)-a(45) from the Ray Ballinger and Wilfrid Keller link by Robert Price, Dec 18 2018 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified October 14 12:02 EDT 2019. Contains 328004 sequences. (Running on oeis4.)