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A168063 Numbers n such that exactly two of {n-2, n-1, n+1, n+2} are primes. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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

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Last modified October 30 06:31 EDT 2020. Contains 338077 sequences. (Running on oeis4.)