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A153276
Numbers n >= 0 such that 5*n+6 is not prime.
1
0, 2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 17, 18, 20, 21, 22, 23, 24, 26, 27, 28, 30, 31, 32, 33, 34, 36, 38, 39, 40, 42, 43, 44, 45, 46, 48, 50, 51, 52, 54, 56, 57, 58, 59, 60, 62, 63, 64, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 80, 81, 82, 84, 86, 87, 88, 89, 90
OFFSET
1,2
COMMENTS
The odd terms are the integer values of (4*h*k + 2*k + 2*h - 5)/5, where h and k are positive integers. - Vincenzo Librandi, Jan 17 2013
The corresponding composite numbers are 6, 16, 21, 26, 36, 46, 51, 56, 66, 76, 81, 86, 91, 96, 106, 111, 116, 121, ... - Michael B. Porter, Jan 17 2013
LINKS
MATHEMATICA
Select[Range[0, 200], !PrimeQ[5 # + 6]&] (* Vincenzo Librandi, Jan 12 2013 *)
PROG
(Magma) [n: n in [0..150] | not IsPrime(5*n + 6)]; // Vincenzo Librandi, Jan 12 2013
CROSSREFS
Cf. A081759.
Sequence in context: A321473 A125292 A101513 * A298866 A108408 A173905
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Dec 22 2008
EXTENSIONS
Erroneous comment deleted by N. J. A. Sloane, Jun 23 2010
Corrected by Jon E. Schoenfield, Jun 24 2010
STATUS
approved