A088680 a(n) = prime(2n+1) - prime(2n).

2, 4, 4, 4, 2, 4, 4, 6, 6, 2, 4, 8, 2, 2, 14, 6, 10, 6, 4, 6, 10, 4, 12, 4, 4, 2, 6, 6, 6, 2, 14, 2, 14, 10, 4, 8, 6, 6, 4, 10, 10, 6, 6, 4, 4, 8, 8, 6, 2, 6, 6, 2, 10, 6, 6, 4, 12, 2, 6, 2, 4, 8, 8, 8, 6, 8, 4, 4, 10, 2, 2, 2, 14, 2, 14, 2, 20, 8, 8, 6, 14, 6, 8, 12, 6, 10, 6, 2, 2, 18, 2, 6, 8, 6, 2

Offset: 1

Author

Zak Seidov, Oct 05 2003

Keywords

• base
• easy
• nonn

Comments

Partition the primes into pairs starting with 3: (3, 5), (7, 11), (13, 17), (19, 23), (29, 31), (37, 41), (43, 47). Sequence gives differences between pairs.

A bisection of A001223.

Crossrefs

Cf. A078584, A088682, A088683, A088684, A078584.

Programs

Mathematica

Table[Prime[2n + 1] - Prime[2n], {n, 100}] (* Robert G. Wilson v, May 29 2004 *)
Differences/@Partition[Prime[Range[2,200]],2]//Flatten (* Harvey P. Dale, Sep 22 2019 *)

Formula

a(n) = A001223(2*n).

Extensions

Edited by Robert G. Wilson v, May 29 2004

Offset corrected. - R. J. Mathar, Feb 23 2017