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A072746 Number of a pairs of primes (p, q) with p<q and (p+q)/2=2^(floor(Log2(q))+1). 2
0, 0, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

As for counting twin primes the convention is followed that a prime pair is <= n if its smaller member is <= n.

LINKS

Table of n, a(n) for n=1..105.

CROSSREFS

Cf. A072742, A072743, A071538.

Sequence in context: A209899 A111898 A279041 * A179528 A105390 A013941

Adjacent sequences:  A072743 A072744 A072745 * A072747 A072748 A072749

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Jul 08 2002

STATUS

approved

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Last modified November 15 09:36 EST 2018. Contains 317232 sequences. (Running on oeis4.)