A033868 Numbers n such that 7*n-11 is prime.

2, 4, 6, 10, 12, 16, 24, 30, 34, 36, 40, 42, 46, 52, 54, 60, 70, 76, 82, 84, 90, 94, 96, 112, 114, 120, 124, 136, 142, 144, 150, 160, 162, 166, 172, 180, 184, 186, 190, 196, 210, 214, 222, 226, 232, 234, 240, 244, 252, 262, 270, 274, 280, 300, 306, 322, 336, 342

Offset: 1

Author

Giovanni Teofilatto, Dec 01 2003

Keywords

• nonn
• easy

References

• M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988.
• Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997.

Links

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

Crossrefs

Cf. A045437 (associated primes), A090613 (gives prime index).

Cf. A024903, A089033, A090614.

Programs

Magma

[n: n in [0..350] | IsPrime(7*n - 11)]; // Vincenzo Librandi, Sep 26 2012

Mathematica

Select[Range[500],PrimeQ[7#-11]&]  (* Harvey P. Dale, Mar 31 2011 *)

PARI

is(n)=isprime(7*n-11) \\ Charles R Greathouse IV, Feb 17 2017

Formula

a(n) = A024903(n)+1 = A089033(n)+2 = A090614(n)*2+2.

Extensions

Extended by Ray Chandler, Dec 23 2003

Offset corrected by Arkadiusz Wesolowski, Aug 09 2011