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A153045 Numbers n such that 2*n-11 is not a prime. 4
10, 13, 16, 18, 19, 22, 23, 25, 28, 30, 31, 33, 34, 37, 38, 40, 43, 44, 46, 48, 49, 51, 52, 53, 55, 58, 61, 63, 64, 65, 66, 67, 68, 70, 72, 73, 76, 77, 78, 79, 82, 83, 85, 86, 88, 90, 91, 93, 94, 97, 98, 99, 100, 103, 106, 107, 108, 109, 110, 112, 113, 114 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The terms are the values of 2*h*k + k + h + 6, where h and k are positive integers.- Vincenzo Librandi, Jan 19 2013

LINKS

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

FORMULA

a(n)= 5+A104275(n+1). [From R. J. Mathar, Oct 22 2009]

MATHEMATICA

Select[Range[10, 200], !PrimeQ[2*#-11]&] (* Vladimir Joseph Stephan Orlovsky, Feb 09 2012 *)

PROG

(MAGMA) [n: n in [7..120] | not IsPrime(2*n - 11)]; // Vincenzo Librandi, Oct 11 2012

CROSSREFS

Cf. A097338, A153043, A163652, A104275.

Sequence in context: A135548 A102502 A309304 * A055984 A282108 A306035

Adjacent sequences:  A153042 A153043 A153044 * A153046 A153047 A153048

KEYWORD

nonn,easy

AUTHOR

Vincenzo Librandi, Dec 17 2008

STATUS

approved

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Last modified July 7 16:09 EDT 2020. Contains 335496 sequences. (Running on oeis4.)