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.
FORMULA
a(n) = A007591(n-1) + 1 for n > 1. [corrected by Georg Fischer, Jun 20 2020]
MATHEMATICA
Select[Range[0, 400, 2], PrimeQ[#^2-2#+5]&] (* Harvey P. Dale, Jan 04 2015 *)
PROG
(Magma) [n: n in [0..100]|IsPrime(n^2-2*n+5)] // Vincenzo Librandi, Nov 16 2010
(PARI) is(n)=isprime(n^2-2*n+5) \\ Charles R Greathouse IV, Jun 13 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Giovanni Teofilatto, Jan 08 2004
STATUS
approved