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A057026 Smallest prime of form (2n+1)*2^m-1 for some m. +0
2
3, 2, 19, 13, 17, 43, 103, 29, 67, 37, 41, 367, 199, 53, 463, 61, 131, 139, 73, 311, 163, 5503, 89, 751, 97, 101, 211, 109, 113, 241663, 487, 251, 1039, 2143, 137, 283, 9343, 149, 307, 157, 647, 331, 2719, 173, 1423, 181, 743, 379, 193, 197, 103423, 823, 419 (list; graph; listen)
OFFSET

0,1

LINKS

Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime

EXAMPLE

a(5)=43 because 2*5+1=11 and smallest prime of the form 11*2^m-1 is 43 (since 10 and 21 are not prime)

CROSSREFS

Cf. A057024, A057025.

Sequence in context: A006281 A078073 A075568 this_sequence A032448 A066195 A090587

Adjacent sequences: A057023 A057024 A057025 this_sequence A057027 A057028 A057029

KEYWORD

nonn

AUTHOR

Henry Bottomley (se16(AT)btinternet.com), Jul 24 2000

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Last modified August 29 17:54 EDT 2008. Contains 143238 sequences.


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