%I

%S 1,1,1,3,1,1,3,1,3,3,7,1,11,1,1,5,1,3,3,1,1,6,3,1,3,7,1,6,3,3,5,4,1,3,

%T 7,7,3,1,9,3,1,4,3,3,3,5,3,6,3,1,5,3,3,1,3,4,1,3,1,7,5,1,3,3,3,1,3,7,

%U 1,9,1,7,9,9,1,12,1,1,5,1,5,3,19,3,3,4,7,3,1,1,5,3,3,11,3,4,11,6,1,3,1,3,11

%N Least k>=1 such that n^2+kn+1 is prime.

%o (PARI) a(n)=if(n<0,0,k=1; while(isprime(n^2+k*n+1)==0,s++); k)

%K nonn

%O 1,4

%A _Benoit Cloitre_, Apr 27 2003