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A092953 Number of primes of the form n+p, where p is a prime < n. 6
0, 0, 1, 1, 1, 1, 0, 2, 1, 2, 1, 3, 0, 2, 1, 3, 1, 3, 0, 3, 1, 2, 0, 6, 0, 4, 1, 3, 1, 6, 0, 3, 0, 4, 1, 6, 0, 4, 1, 5, 1, 8, 0, 4, 1, 4, 0, 7, 0, 6, 1, 4, 0, 9, 0, 8, 1, 4, 1, 11, 0, 5, 0, 5, 1, 11, 0, 6, 1, 8, 1, 9, 0, 4, 0, 7, 1, 11, 0, 7, 1, 4, 0, 13, 0, 7, 1, 5, 0, 15, 0, 7, 0, 8, 1, 13, 0, 8, 1, 9, 1, 11 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

COMMENTS

Might be called as the additive primability of n.

a(A007921(n))=0; for n>2: a(A030173(n))>0 and a(A040976(n))=1. - Reinhard Zumkeller, Nov 10 2012

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

EXAMPLE

a(26) = 4: the primes are 29, 31, 37 and 43.

PROG

(PARI) for(n=1, 105, c=0; forprime(p=2, n-1, if(isprime(n+p), c++)); print1(c, ", "))

(Haskell)

a092953 n = sum $

   zipWith (\u v -> a010051' u * a010051' v) [1 .. n - 1] [n + 1 ..]

-- Reinhard Zumkeller, Nov 10 2012

CROSSREFS

Cf. A092954.

Cf. A061357.

Sequence in context: A113738 A287854 A245714 * A058574 A112165 A112186

Adjacent sequences:  A092950 A092951 A092952 * A092954 A092955 A092956

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Mar 24 2004

EXTENSIONS

More terms from Klaus Brockhaus and Mohammed Bouayoun (bouyao(AT)wanadoo.fr), Mar 25 2004

STATUS

approved

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Last modified November 28 16:42 EST 2021. Contains 349413 sequences. (Running on oeis4.)