cp's OEIS Frontend

A002259 Numbers k such that 17*2^k + 1 is prime.

%I A002259 M2985 N1206 #38 Dec 22 2024 09:29:11
%S A002259 3,15,27,51,147,243,267,347,471,747,2163,3087,5355,6539,7311,99231,
%T A002259 824451,1388355,1990299,8636199
%N A002259 Numbers k such that 17*2^k + 1 is prime.
%D A002259 H. Riesel, "Prime numbers and computer methods for factorization", Progress in Mathematics, Vol. 57, Birkhauser, Boston, 1985, Chap. 4, see pp. 381-384.
%D A002259 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A002259 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A002259 Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a>
%H A002259 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 A002259 Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a>
%H A002259 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a>
%H A002259 R. M. Robinson, <a href="https://doi.org/10.1090/S0002-9939-1958-0096614-7">A report on primes of the form k.2^n+1 and on factors of Fermat numbers</a>, Proc. Amer. Math. Soc., 9 (1958), 673-681.
%H A002259 <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 A002259 (PARI) is(n)=ispseudoprime(17*2^n+1) \\ _Charles R Greathouse IV_, Jun 06 2017
%K A002259 hard,more,nonn
%O A002259 1,1
%A A002259 _N. J. A. Sloane_
%E A002259 Added more terms (from http://web.archive.org/web/20161028080239/http://www.prothsearch.net/riesel.html), _Joerg Arndt_, Apr 07 2013
%E A002259 a(20) from _Jeppe Stig Nielsen_, Dec 22 2024