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 A005849 Prime Cullen numbers: numbers n such that n*2^n + 1 is prime. (Formerly M5401) 20
 1, 141, 4713, 5795, 6611, 18496, 32292, 32469, 59656, 90825, 262419, 361275, 481899, 1354828, 6328548, 6679881 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 REFERENCES J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 141, p. 48, Ellipses, Paris 2008. Harvey Dubner, Generalized Cullen numbers, J. Rec. Math., 21 (No. 3, 1989), 190-191. Paulo Ribenboim, The Book of Prime Number Records. Springer-Verlag, NY, 2nd ed., 1989, p. 283. N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS Ray Ballinger, Cullen Primes: Definition and Status Chris K. Caldwell, The Top Twenty: Cullen Primes H. Dubner, Generalized Cullen numbers, J. Rec. Math., 21 (No. 3, 1989), 190-191. (Annotated scanned copy) R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations Eric Weisstein's World of Mathematics, Cullen Number Eric Weisstein's World of Mathematics, Integer Sequence Primes MATHEMATICA Select[Range[1000], PrimeQ[# 2^# + 1] &] (* Alonso del Arte, Jul 30 2017 *) PROG (PARI) is(n)=isprime(n<

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Last modified December 15 15:44 EST 2018. Contains 318150 sequences. (Running on oeis4.)