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 A002259 Numbers n such that 17*2^n+1 is prime. (Formerly M2985 N1206) 2
 3, 15, 27, 51, 147, 243, 267, 347, 471, 747, 2163, 3087, 5355, 6539, 7311, 99231, 824451, 1388355, 1990299 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 REFERENCES H. Riesel, ``Prime numbers and computer methods for factorization,'' Progress in Mathematics, Vol. 57, Birkhauser, Boston, 1985, Chap. 4, see pp. 381-384. N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence). N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). 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 R. M. Robinson, A report on primes of the form k.2^n+1 and on factors of Fermat numbers, Proc. Amer. Math. Soc., 9 (1958), 673-681. PROG (PARI) is(n)=ispseudoprime(17*2^n+1) \\ Charles R Greathouse IV, Jun 06 2017 CROSSREFS Sequence in context: A080065 A017557 A147041 * A050848 A077785 A222291 Adjacent sequences:  A002256 A002257 A002258 * A002260 A002261 A002262 KEYWORD hard,more,nonn AUTHOR EXTENSIONS Added more terms (from http://web.archive.org/web/20161028080239/http://www.prothsearch.net/riesel.html), Joerg Arndt, Apr 07 2013 STATUS approved

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Last modified November 28 07:44 EST 2020. Contains 338702 sequences. (Running on oeis4.)