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

1,1

Comments

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

Links

Table of n, a(n) for n=1..53.

Formula

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

Example

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.

Sequence in context: A368768 A297206 A373388 * A122045 A294314 A347599

Adjacent sequences: A103706 A103707 A103708 * A103710 A103711 A103712

Keyword

nonn

Author

Zak Seidov, Feb 12 2005

Extensions

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

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

Status

approved