A237283 Primes p with prime(prime(p)) + 2 also prime.

2, 3, 7, 13, 23, 29, 59, 71, 103, 193, 257, 271, 281, 311, 317, 389, 433, 439, 463, 569, 577, 619, 673, 683, 691, 797, 811, 857, 859, 887, 1031, 1069, 1109, 1129, 1153, 1229, 1307, 1597, 1613, 1867, 1949, 1951, 2069, 2297, 2477, 2551, 2621, 2657, 2699, 2753

Offset

1,1

Comments

This sequence is interesting because of the conjecture in A237253.

A236481, A236482 and A236484 are subsequences of the sequence.

Links

Zhi-Wei Sun, Table of n, a(n) for n = 1..10000

Example

a(1) = 2 since 2 and prime(prime(2)) + 2 = prime(3) + 2 = 7 are both prime.

Mathematica

n=0; Do[If[PrimeQ[Prime[Prime[Prime[k]]]+2], n=n+1; Print[n, " ", Prime[k]]], {k, 1, 1000}]
Select[Prime[Range[500]], PrimeQ[Prime[Prime[#]]+2]&] (* Harvey P. Dale, May 30 2018 *)

Crossrefs

Cf. A000040, A001359, A006512, A096478, A218829, A236457, A236458, A236467, A236481, A236482, A236484, A236568, A237253.

Sequence in context: A238432 A238423 A133370 * A332861 A182047 A291544

Adjacent sequences: A237280 A237281 A237282 * A237284 A237285 A237286

Keyword

nonn

Author

Zhi-Wei Sun, Feb 05 2014

Status

approved