A078584 a(n) = prime(2n) - prime(2n-1).

1, 2, 2, 2, 6, 6, 2, 6, 2, 4, 6, 6, 4, 4, 4, 4, 2, 2, 6, 6, 2, 2, 2, 12, 2, 6, 10, 6, 2, 4, 10, 4, 4, 6, 2, 6, 6, 4, 8, 8, 2, 2, 4, 8, 2, 12, 4, 4, 12, 18, 10, 6, 6, 6, 2, 6, 2, 10, 4, 6, 12, 6, 10, 10, 6, 4, 6, 8, 14, 12, 10, 4, 10, 4, 4, 4, 4, 4, 10, 4, 6, 4, 6, 6, 4, 2, 2, 10, 10, 6, 4, 4, 6, 6, 22, 10

Offset: 1

Author

Robert G. Wilson v, Nov 30 2002

Keywords

• nonn
• easy

Comments

First differences of A077133. Bisection of A001223.

Partition the primes in pairs starting with 5: (5, 7), (11, 13), (17, 19), (23, 29), (31, 37), (41, 43), (47, 53). Sequence gives differences between pairs. - Zak Seidov, Oct 05 2003

Examples

			a(4)=6 as a_o(5)=58 - a_e(5)=71 is 13 and a_o(4)=35 - a_e(4)=42 is 7 and the difference is 6.
		

Crossrefs

Cf. A000040, A088680, A088682, A088683, A088684.

Programs

Mathematica

Table[ Prime[2n] - Prime[2n - 1], {n, 100}] (* Robert G. Wilson v, May 29 2004 *)

Extensions

Edited by N. J. A. Sloane, Sep 15 2008 at the suggestion of R. J. Mathar