A167833 Three-times-isolated primes: primes p such that neither p+-2, p+-4 nor p+-6 is prime.

2, 211, 293, 409, 479, 631, 691, 701, 709, 719, 787, 797, 839, 919, 929, 1163, 1171, 1201, 1249, 1259, 1381, 1399, 1409, 1471, 1511, 1523, 1531, 1637, 1709, 1733, 1801, 1811, 1823, 1831, 1847, 1889, 2039, 2053, 2099, 2153, 2161, 2179, 2221, 2251, 2459

Offset

1,1

Comments

2 together with prime numbers, isolated from neighboring primes by>6.

Links

Harvey P. Dale, Table of n, a(n) for n = 1..2500

Example

a(1)=2 (-4,-2,0,4,6,8 are nonprimes); a(2)=211 (205,207,209,213,215,217 are nonprimes).

Mathematica

Join[{2}, Select[Prime[Range[400]], NoneTrue[#+{2, 4, 6, -2, -4, -6}, PrimeQ]&]] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 16 2019 *)

Crossrefs

Cf. A137870, A167771.

Sequence in context: A056065 A317978 A050445 * A167838 A106100 A167839

Adjacent sequences: A167830 A167831 A167832 * A167834 A167835 A167836

Keyword

nonn

Author

Juri-Stepan Gerasimov, Nov 13 2009

Status

approved