A138645 Primes p such that 7*p+2 is composite.

2, 7, 13, 17, 19, 29, 31, 37, 41, 43, 59, 61, 67, 73, 79, 83, 89, 97, 103, 109, 113, 127, 137, 139, 149, 151, 157, 163, 179, 181, 191, 193, 199, 211, 223, 227, 229, 233, 239, 241, 263, 269, 271, 277, 281, 283, 307, 313, 331, 337, 347, 349, 359, 367, 373, 379

Offset

1,1

Links

Table of n, a(n) for n=1..56.

Example

7*2+2=16, 7*7+2=51, 7*13+2=93,...

Mathematica

a={}; Do[p=Prime[n]; If[ !PrimeQ[7*p+2], AppendTo[a, p]], {n, 8^2}]; a
Select[Prime[Range[200]], !PrimeQ[7#+2]&] (* Harvey P. Dale, Aug 05 2011 *)

Crossrefs

Cf. A153351.

Sequence in context: A154313 A196012 A065104 * A191060 A166246 A250185

Adjacent sequences: A138642 A138643 A138644 * A138646 A138647 A138648

Keyword

nonn

Author

Vladimir Joseph Stephan Orlovsky, May 15 2008

Extensions

More terms from Vincenzo Librandi, Apr 01 2010

Status

approved