A145061 Number of pairs of odd numbers that separate two consecutive twin prime pairs.

0, 2, 2, 5, 5, 8, 5, 14, 2, 14, 5, 14, 5, 2, 14, 5, 14, 5, 14, 17, 35, 5, 14, 29, 23, 14, 8, 11, 8, 74, 5, 2, 14, 11, 68, 5, 8, 5, 14, 29, 38, 23, 5, 5, 8, 53, 11, 14, 2, 59, 5, 23, 14, 11, 32, 41, 2, 26, 8, 23, 14, 26, 2, 11, 8, 5, 47, 14, 20, 14, 20

Offset: 1

Author

John Austin Curry (acurry(AT)mckoolsmith.com), Sep 30 2008

Keywords

• nonn

Comments

Example: a(3) = 2 because the third twin prime pair is (11, 13) and there are two pairs of odd numbers between (11, 13) and its immediate predecessor, (5,7), namely (7, 9) and (9, 11).

Programs

PARI

lista(nn) = {prm = primes(nn); gtp = select(p->isprime(p-2), prm); ltp = select(p->isprime(p+2), prm); for (i=1, #ltp-1, print1((ltp[i+1] - gtp[i])/2, ", "););} \\ Michel Marcus, Sep 04 2013

Formula

a(n) = (A001359(n+1) - (A001359(n) + 2))/2 = (A001359(n+1) - A006512(n))/2. - Michel Marcus, Sep 04 2013

Extensions

More terms from Michel Marcus, Sep 04 2013