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A002234
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Numbers k such that the Woodall number k*2^k - 1 is prime.
(Formerly M0820 N0311)
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29
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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, 17016602
(list;
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listen;
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OFFSET
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1,1
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COMMENTS
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a(34) = 17016602 is tentative until the range 16838832..17016601 is fully searched. - Eric W. Weisstein, Mar 22 2018
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REFERENCES
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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).
David Wells, The Penguin Dictionary of Curious and Interesting Numbers. Penguin Books, NY, 1986, Revised edition 1987. See p. 139.
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LINKS
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Brady Haran and Matt Parker, 383 is cool, Numberphile video (2017).
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PROG
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CROSSREFS
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KEYWORD
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nonn,nice,hard,changed
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AUTHOR
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EXTENSIONS
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a(27) communicated by Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 15 2004
a(28) = 1195203 found by M. Rodenkirch; 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
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STATUS
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approved
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