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 A002274 Numbers k such that 57*2^k+1 is prime. (Formerly M0822 N0313) 2
 2, 3, 7, 8, 10, 16, 18, 19, 40, 48, 55, 90, 96, 98, 190, 398, 456, 502, 719, 1312, 1399, 1828, 6723, 6816, 10680, 12592, 20742, 25010, 26838, 29623, 45435, 52783, 70950, 89691, 111691, 114400, 136152, 145183, 146223, 177459, 212908, 300910, 342151, 360447, 382156, 411635, 442948, 519862, 519892, 975036, 1158942, 1181438, 1756702, 2033643 (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 and Wilfrid Keller, List of primes k.2^n + 1 for k < 300 Ray Ballinger, Proth Search Page 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(57*2^n+1) \\ Charles R Greathouse IV, May 22 2017 CROSSREFS Sequence in context: A206821 A323003 A051468 * A329783 A287675 A273944 Adjacent sequences:  A002271 A002272 A002273 * A002275 A002276 A002277 KEYWORD hard,nonn AUTHOR EXTENSIONS More terms from Hugo Pfoertner, Jun 20 2003 More terms (from http://web.archive.org/web/20161028080239/http://www.prothsearch.net/riesel.html), Joerg Arndt, Apr 07 2013 a(54) from http://www.prothsearch.com/riesel1.html by Robert Price, Dec 14 2018 STATUS approved

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Last modified April 21 17:36 EDT 2021. Contains 343156 sequences. (Running on oeis4.)