A136049 a(n)=number of primes p such that (p,p+2) is a pair of twin primes with n^2 + n < p < n^2+3*n+2.

2, 1, 1, 1, 1, 0, 2, 0, 2, 0, 2, 1, 2, 2, 1, 1, 1, 1, 1, 2, 0, 1, 2, 2, 1, 0, 1, 3, 1, 0, 3, 2, 1, 1, 4, 0, 3, 1, 2, 3, 1, 2, 2, 2, 5, 1, 3, 1, 1, 1, 4, 2, 1, 1, 2, 3, 4, 4, 2, 2, 2, 4, 4, 5, 2, 3, 2, 3, 2, 3, 1, 1, 5, 3, 2, 2, 2, 3, 2, 2, 6, 4, 1, 2, 3, 4, 1, 3, 1, 3, 3, 2, 3, 4, 2, 5, 2, 3, 5, 3, 4, 2, 2, 4, 2

Offset

1,1

Links

Pierre CAMI, Table of n, a(n) for n = 1..5000

Example

For n=1 we can take p = 3 and p = 5, with twin primes (3 5) and (5 7) and 3 and 5 are > 2 and < 6 so a(1)=2

Crossrefs

Sequence in context: A256983 A330720 A080234 * A370219 A225192 A262432

Adjacent sequences: A136046 A136047 A136048 * A136050 A136051 A136052

Keyword

nonn

Author

Pierre CAMI, Dec 12 2007; corrected Jan 24 2008

Extensions

Verified by Don Reble, Jun 22 2008, including the b-file.

Status

approved