A176164 Primes p such that (p-2)/7 is not a prime number.

2, 3, 5, 7, 11, 13, 17, 19, 29, 31, 41, 43, 47, 53, 59, 61, 67, 71, 73, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293

Offset

1,1

Comments

The old definition was "Start with the list of primes; accept 2 but remove the list of primes S(2); accept the next prime (3) but remove the list of primes S(3); repeat".

If p is a prime, S(p) denotes the list of primes {7p+2, 7(7p+2)+2, 7(7(7p+2)+2)+2, ...}, stopping as soon as we reach the first composite number.

Links

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

Mathematica

Select[Prime[Range[70]], !PrimeQ[(#-2)/7]&]  (* Harvey P. Dale, Mar 17 2011 *)

Prog

(Magma) [p: p in PrimesUpTo(300)| not IsPrime((p-2)/7)]; // Vincenzo Librandi, Sep 12 2013

Crossrefs

Cf. A169647, A176162.

Sequence in context: A127052 A092570 A133956 * A141409 A238647 A348358

Adjacent sequences: A176161 A176162 A176163 * A176165 A176166 A176167

Keyword

nonn,easy

Author

Vincenzo Librandi, Apr 10 2010

Extensions

New definition from Jon E. Schoenfield, Jun 18 2010

Status

approved