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A029544
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Near Cullen numbers: k such that (k+1)*2^k + 1 is prime.
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4
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0, 1, 2, 5, 6, 13, 26, 65, 66, 86, 114, 133, 186, 294, 445, 866, 1325, 1478, 1823, 2765, 7553, 7943, 10178, 20960, 20964, 21337, 26562, 85374, 96749, 247038
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OFFSET
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1,3
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COMMENTS
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Primes in the sequence are 2, 5, 13, 1823, 96749, ... - R. J. Mathar, Oct 15 2011
We can write (k+1)*2^k + 1 = {(k+1)/2}*4^{(k+1)/2} + 1, and when k is odd, this takes the form of a generalized Cullen prime (base 4). These are listed in A007646. In other words, {2*A007646 - 1} gives all the odd terms of this sequence. - Jeppe Stig Nielsen, Oct 16 2019
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LINKS
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PROG
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(PARI) isok(n) = isprime((n+1)*2^n+1); \\ Michel Marcus, Nov 09 2013
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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Corrected and extended by Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 05 2008
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STATUS
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approved
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