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A069923 Number of primes p such that 2^n<=p<=2^n+prime(n). +0
1
2, 2, 2, 3, 3, 3, 3, 4, 2, 5, 3, 5, 5, 4, 7, 9, 4, 5, 5, 7, 3, 4, 7, 3, 7, 6, 8, 6, 5, 8, 4, 6, 10, 3, 5, 3, 7, 6, 7, 7, 8, 6, 7, 5, 7, 5, 8, 4, 2, 7, 6, 6, 7, 3, 6, 6, 11, 6, 6, 9, 8, 8, 7, 7, 6, 6, 10, 8, 7, 10, 9, 7, 5, 5, 9, 6, 8, 11, 9, 5, 8, 6, 10, 9, 5, 9, 12, 6, 7, 4, 7, 6, 9, 8, 5, 7, 6, 7, 3, 4, 8 (list; graph; listen)
OFFSET

1,1

COMMENT

For any n>0 is there always at least one prime p such that 2^n<=p<=2^n+prime(n)? (checked until n=250 ) In this case, that would be stronger than the Schinzel conjecture : "for m >1 there's at least one prime p such that m<=p<=m+ln(m)^2" since for n >2 prime(n)<ln(2^n)^2=n^2*ln(2).

PROGRAM

(PARI) for(n=1, 65, print1(sum(i=2^n, 2^n+prime(n), isprime(i)), ", "))

CROSSREFS

Cf. A014210.

Sequence in context: A127240 A097561 A048689 this_sequence A095840 A131343 A089051

Adjacent sequences: A069920 A069921 A069922 this_sequence A069924 A069925 A069926

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre (benoit7848c(AT)orange.fr), May 05 2002

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Last modified November 21 14:49 EST 2008. Contains 150807 sequences.


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