A089373 Numbers k such that k^2 - 7*k + 7 is prime.

0, 7, 10, 12, 15, 16, 22, 25, 27, 31, 36, 37, 40, 46, 51, 52, 55, 57, 60, 61, 67, 75, 85, 87, 90, 97, 102, 106, 111, 120, 136, 151, 156, 157, 162, 171, 172, 177, 180, 186, 192, 202, 205, 211, 220, 222, 225, 237, 240, 241, 250, 255, 261, 267, 271, 277, 282, 286, 291, 292

Offset

1,2

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..10000

Mathematica

Column[(0), Select[Range[6, 200], PrimeQ[ #^2-7#+7]&]] (* Vincenzo Librandi, Dec 12 2011 *)

Prog

(Magma) [0], [n: n in [6..300] | IsPrime(n^2 - 7*n + 7)]; // Vincenzo Librandi, Dec 12 2011
(PARI) is(n)=isprime(n^2-7*n+7) \\ Charles R Greathouse IV, May 22 2017
(GAP) Concatenation([0], Filtered([7..300], k->IsPrime(k^2-7*k+7))); # Muniru A Asiru, Nov 24 2018

Crossrefs

Cf. A089376 (primes of the form k^2 - 7*k + 7).

Sequence in context: A128783 A024586 A050419 * A184114 A345478 A295797

Adjacent sequences: A089370 A089371 A089372 * A089374 A089375 A089376

Keyword

easy,nonn

Author

Giovanni Teofilatto, Dec 27 2003

Extensions

More terms from David Wasserman, Sep 15 2005

a(1)=0 inserted by Vincenzo Librandi, Dec 12 2011

Status

approved