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

1,1

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

Mathematica

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

Crossrefs

Cf. A001097(twin primes), A283265.

Sequence in context: A141409 A238647 A348358 * A004051 A127047 A119615

Adjacent sequences: A171818 A171819 A171820 * A171822 A171823 A171824

Keyword

nonn

Author

Juri-Stepan Gerasimov, Dec 19 2009

Extensions

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

Status

approved