A032400 - OEIS

%I #31 Apr 20 2020 02:42:15

%S 3,9,17,21,27,39,45,47,71,95,117,123,143,173,387,389,513,633,827,971,

%T 1103,3767,3831,7695,8871,9809,10011,17513,17873,22841,25401,84369,

%U 95315,168983,382407,488039,534891,687897,715503,1142981,1988279,2009735,2212769

%N Numbers k such that 101*2^k+1 is prime.

%H Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a>

%H Ray Ballinger and Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a>

%H Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a>

%H Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a>

%H <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a>

%o (PARI) is(n)=ispseudoprime(101*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn

%O 1,1

%A _James R. Buddenhagen_

%E More terms from _Hugo Pfoertner_, Jun 20 2003

%E More terms (from http://web.archive.org/web/20161028080239/http://www.prothsearch.net/riesel.html), _Joerg Arndt_, Apr 07 2013

%E a(41)-a(42) from http://www.prothsearch.com/riesel1.html by _Robert Price_, Dec 14 2018

%E a(43) from _Jeppe Stig Nielsen_, Apr 19 2020