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A002234 Numbers n such that the Woodall number n*2^n - 1 is prime.
(Formerly M0820 N0311)
12
2, 3, 6, 30, 75, 81, 115, 123, 249, 362, 384, 462, 512, 751, 822, 5312, 7755, 9531, 12379, 15822, 18885, 22971, 23005, 98726, 143018, 151023, 667071, 1195203, 1268979, 1467763, 2013992, 2367906, 3752948 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

No other terms < 6500000. - John Blazek, May 14 2009

REFERENCES

J.-M. De Koninck, Ces nombres qui nous fascinent, Entry 115, p. 40, Ellipses, Paris 2008.

F. Le Lionnais, Les Nombres Remarquables, Paris, Hermann, 1983, p. 95, 1983.

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

Table of n, a(n) for n=1..33.

Ray Ballinger, Woodall Primes: Definition and Status

Ray Ballinger and Wilfrid Keller, Woodall numbers

C. K. Caldwell, Woodall Numbers

J. DeMaio, Generalized Woodall Numbers

R. Ondrejka, The Top Ten: a Catalogue of Primal Configurations

PrimeGrid, PrimeGrid Primes: Subproject: (WOO) Woodall Prime Search

H. Riesel, Lucasian criteria for the primality of N=h.2^n-1, Math. Comp., 23 (1969), 869-875.

Eric Weisstein's World of Mathematics, Woodall Number

Eric Weisstein's World of Mathematics, Integer Sequence Primes

CROSSREFS

Cf. A050918 (for the actual primes), A003261, A005849.

Sequence in context: A051717 A192441 A108326 * A074005 A145499 A221310

Adjacent sequences:  A002231 A002232 A002233 * A002235 A002236 A002237

KEYWORD

nonn,nice,hard

AUTHOR

N. J. A. Sloane, Simon Plouffe

EXTENSIONS

a(27) communicated by Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 15 2004

1195203 found by M. Rodenkirch, but the region from 1020000 to 1195203 is incompletely searched; contributed by Eric W. Weisstein, Nov 29 2005

More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008

1467763, 2013992, 2367906, 3752948 from John Blazek, May 14 2009

STATUS

approved

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Last modified February 13 16:02 EST 2016. Contains 268279 sequences.