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A076608 Number of nonprimes k < n such that also n-k is not a prime. 0
0, 1, 0, 0, 2, 0, 2, 1, 2, 4, 2, 3, 4, 4, 4, 7, 4, 7, 6, 7, 6, 10, 6, 11, 8, 12, 8, 13, 10, 15, 12, 13, 12, 18, 12, 21, 14, 16, 16, 21, 16, 23, 18, 21, 18, 24, 18, 27, 20, 27, 20, 27, 22, 31, 24, 29, 24, 32, 26, 37, 28, 30, 28, 37, 28, 41, 30, 33, 32, 41, 32, 43, 34, 40, 34, 43, 34 (list; graph; refs; listen; history; internal format)
OFFSET

1,5

COMMENTS

a(n) is odd iff n is even and n/2 is not prime.

EXAMPLE

5=1+4=2+3=3+2=4+1, hence a(5)=2;

6=1+5=2+4=3+3=4+2=5+1, hence a(6)=0.

CROSSREFS

Cf. A073610.

Sequence in context: A125922 A182893 A206298 * A068461 A130456 A071497

Adjacent sequences:  A076605 A076606 A076607 * A076609 A076610 A076611

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 21 2002

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Last modified February 13 17:19 EST 2012. Contains 205523 sequences.