A103709 Smallest prime p such that both p +/- 2n are primes closest to p, or zero if no such prime exists.

5, 0, 53, 0, 0, 211, 0, 0, 20201, 0, 0, 16787, 0, 0, 69623, 0, 0, 255803, 0, 0, 247141, 0, 0, 3565979, 0, 0, 6314447, 0, 0, 4911311, 0, 0, 12012743, 0, 0, 23346809, 0, 0, 43607429, 0, 0, 34346287, 0, 0, 36598607, 0, 0, 51042053, 0, 0, 460475569, 0, 0

Offset: 1

Author

Zak Seidov, Feb 12 2005

Keywords

• nonn

Comments

Such triples of primes occur only for n divisible by 3 (except for the first term with n=1).

Examples

			a(36)=23346809 because 23346809-72, 23346809 and 23346809+72 are three successive primes and 23346809 is the least such prime.
		

Crossrefs

Cf. A054342, A102723, A023186.

Formula

p-2n, p and p+2n are three successive primes and p is the least such prime.

Extensions

More terms from Robert G. Wilson v, Feb 22 2005

Definition, Formula, and Example clarified by Jonathan Sondow, Oct 27 2017