

A153052


Numbers n such that 2*n + 5 is not a prime.


4



2, 5, 8, 10, 11, 14, 15, 17, 20, 22, 23, 25, 26, 29, 30, 32, 35, 36, 38, 40, 41, 43, 44, 45, 47, 50, 53, 55, 56, 57, 58, 59, 60, 62, 64, 65, 68, 69, 70, 71, 74, 75, 77, 78, 80, 82, 83, 85, 86, 89, 90, 91, 92, 95, 98, 99, 100, 101, 102, 104, 105, 106, 107, 108, 110
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OFFSET

1,1


COMMENTS

One less than the associated entry in A153238.  R. J. Mathar, Jan 05 2011
The terms are the values of 2*h*k + k + h  2, where h and k are positive integers. Vincenzo Librandi, Jan 19 2013


LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000


MATHEMATICA

Select[Range[0, 150], !PrimeQ[2*# + 5] &] (* Vincenzo Librandi, Oct 16 2012 *)


PROG

(MAGMA) [n: n in [0..110] not IsPrime(2*n+5)]; // Vincenzo Librandi, Oct 16 2012


CROSSREFS

Cf. A089038, A154680.
Sequence in context: A078345 A161817 A080228 * A338388 A237525 A290578
Adjacent sequences: A153049 A153050 A153051 * A153053 A153054 A153055


KEYWORD

nonn,easy


AUTHOR

Vincenzo Librandi, Dec 17 2008


STATUS

approved



