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A013597
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nextprime(2^n)-2^n.
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12
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1, 1, 1, 3, 1, 5, 3, 3, 1, 9, 7, 5, 3, 17, 27, 3, 1, 29, 3, 21, 7, 17, 15, 9, 43, 35, 15, 29, 3, 11, 3, 11, 15, 17, 25, 53, 31, 9, 7, 23, 15, 27, 15, 29, 7, 59, 15, 5, 21, 69, 55, 21, 21, 5, 159, 3, 81, 9, 69, 131, 33, 15, 135, 29, 13, 131, 9, 3, 33, 29, 25, 11, 15, 29
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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COMMENTS
| A013597 and A092131 use different definitions of "nextprime(2)". A013597 assumes nextprime(2)=3, whereas A092131 assumes nextprime(2)=2.
If (for n>0) a(n)=1, then n is a power of 2 and 2^n+1 is a Fermat prime. n=1,2,4,8,16 are probably the only indices with this property. - Franz Vrabec (franz.vrabec(AT)aon.at), Sep 27 2005
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LINKS
| T. D. Noe, Table of n, a(n) for n=0..5000
V. Danilov, Table for large n
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MAPLE
| seq(nextprime(2^i)-2^i, i=0..100);
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CROSSREFS
| Cf. A014210.
Cf. A092131.
Sequence in context: A135224 A152203 A161946 * A092131 A092099 A096567
Adjacent sequences: A013594 A013595 A013596 * A013598 A013599 A013600
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KEYWORD
| nonn
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AUTHOR
| James Kilfiger (mapdn(AT)csv.warwick.ac.uk)
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