A171821 2 together with twin primes.

2, 3, 5, 7, 11, 13, 17, 19, 29, 31, 41, 43, 59, 61, 71, 73, 101, 103, 107, 109, 137, 139, 149, 151, 179, 181, 191, 193, 197, 199, 227, 229, 239, 241, 269, 271, 281, 283, 311, 313, 347, 349, 419, 421, 431, 433, 461, 463, 521, 523, 569, 571, 599, 601, 617, 619, 641

Offset: 1

Author

Juri-Stepan Gerasimov, Dec 19 2009

Keywords

• nonn

Comments

Primes of the form p-1, p-2 and p+2 for p prime. - Juri-Stepan Gerasimov, Apr 30 2010

Numbers n such that A283265(n) = 0. - Mats Granvik, Mar 18 2017

Links

• Michael De Vlieger, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001097(twin primes), A283265.

Programs

Mathematica

Union@ Flatten@ Select[Partition[#, 2, 1] &@ Prime@ Range@ 117, First@ Differences@ # <= 2 &] (* Michael De Vlieger, Mar 18 2017 *)

Extensions

Entries checked by D. S. McNeil, Nov 26 2010