A153276 Numbers n >= 0 such that 5*n+6 is not prime.

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

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

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

Adjacent sequences: A153273 A153274 A153275 * A153277 A153278 A153279

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