A089358 Numbers k such that k^2 - 3*k + 3 is prime.

3, 4, 5, 7, 8, 10, 14, 16, 17, 19, 22, 23, 26, 29, 35, 40, 43, 52, 56, 59, 61, 64, 68, 71, 73, 77, 79, 80, 82, 91, 92, 101, 103, 107, 112, 113, 119, 121, 133, 140, 143, 145, 149, 152, 155, 157, 163, 164, 166, 169, 170, 175, 178, 190, 191, 194, 196, 205, 208

Offset: 1

Author

Giovanni Teofilatto, Dec 27 2003

Keywords

• easy
• nonn
• changed

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

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Mathematica

Select[Range[210],PrimeQ[#^2-3#+3]&] (* Harvey P. Dale, Mar 23 2012 *)

PARI

is(n)=isprime(n^2-3*n+3) \\ Charles R Greathouse IV, Jun 12 2017

Formula

a(n) = A002384(n)+2.

Extensions

Corrected by Harvey P. Dale, Mar 23 2012