%I #16 Sep 08 2022 08:45:01
%S 2,3,4,6,7,9,13,15,16,18,21,22,25,28,34,39,42,51,55,58,60,63,67,70,72,
%T 76,78,79,81,90,91,100,102,106,111,112,118,120,132,139,142,144,148,
%U 151,154,156,162,163,165,168,169,174,177,189,190,193,195,204,207,210,216
%N Numbers k such that k^2 - k + 1 is prime.
%D M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988
%D D. E. Knuth, "The Art of Computer Programming," Addison-Wesley, Reading, MA, Volume II, page 378.
%D Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997
%H Vincenzo Librandi, <a href="/A055494/b055494.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Range[300], PrimeQ[#^2 - # + 1] &] (* _Vincenzo Librandi_, Sep 28 2012 *)
%o (Magma) [n: n in [1..300] |IsPrime(n^2 - n + 1)]; // _Vincenzo Librandi_, Sep 28 2012
%o (PARI) is(n)=isprime(n^2-n+1) \\ _Charles R Greathouse IV_, Feb 16 2017
%Y Equals A002384(n)+1.
%Y A002383 gives the primes.
%K nonn,easy
%O 1,1
%A _Robert G. Wilson v_, Jul 05 2000
%E More terms from _David Wasserman_, Sep 15 2005