A139394 a(n) = A024899(n)-A024898(n).

0, 0, 0, 1, 1, 0, 2, 2, 2, 1, 2, 2, 1, 3, 4, 3, 3, 2, 2, 3, 3, 3, 4, 0, 1, 5, 4, 4, 7, 7, 8, 7, 6, 8, 4, 4, 6, 4, 5, 5, 3, 4, 3, 6, 6, 9, 10, 9, 11, 11, 13, 8, 8, 8, 7, 8, 10, 9, 8, 10, 12, 12, 10, 11, 9, 8, 7, 8, 8, 5, 7, 6, 8, 7, 8, 9, 9, 13, 13, 11, 11, 12, 13, 11, 12, 13, 9, 11, 10, 11, 10, 6, 9

Offset: 1

Author

Zak Seidov, Apr 18 2008

Keywords

• nonn
• look

Comments

From Zak Seidov, Nov 12 2008: (Start)

Conjecture: a(n) > 0, except n=1,2,3,6,24, when a(n)=0.

This fact can be apparently explained by existence of twin primes. (End)

Links

• Zak Seidov, Table of n, a(n) for n = 1..3000.
• Zak Seidov, A024899(n) > A024898(n) [From _Zak Seidov_, Nov 12 2008]

Crossrefs

Cf. A024898, A024899.