A168063 Numbers k such that exactly two of {k-2, k-1, k+1, k+2} are primes.

1, 3, 5, 6, 9, 12, 15, 18, 21, 30, 39, 42, 45, 60, 69, 72, 81, 99, 102, 105, 108, 111, 129, 138, 150, 165, 180, 192, 195, 198, 225, 228, 231, 240, 270, 279, 282, 309, 312, 315, 348, 351, 381, 399, 420, 432, 441, 459, 462, 465, 489, 501, 522, 570, 600, 615, 618

Offset

1,2

Comments

Essentially the same as A014574 U A087679. - Charles R Greathouse IV, May 25 2011

Links

G. C. Greubel, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[700], Count[#+{-2, -1, 1, 2}, _?PrimeQ]==2&] (* Harvey P. Dale, Jan 24 2014 *)

Crossrefs

Cf. A014574, A087679.

Sequence in context: A192577 A236343 A325420 * A039873 A096394 A075472

Adjacent sequences: A168060 A168061 A168062 * A168064 A168065 A168066

Keyword

nonn,easy

Author

Juri-Stepan Gerasimov, Nov 18 2009

Extensions

Corrected (105 inserted, 609 removed) by R. J. Mathar, Jun 04 2010

Status

approved