A128968 - OEIS

%I #5 Aug 30 2016 14:14:00

%S 2,3,19,53,2309,967,151,6569,3373,2819,15887,2221,3613,81239,4639,

%T 6257,101141,6907,35363,106949,59557,6911,49307,70249,10429,408347,

%U 33151,9437,518429,63031,40031,159233,155269,66083,725939,156061,13033,641639

%N a(n) is the n-th prime of the form x^2+n.

%e a(4)=53 because 5=1^2+4,13=3^2+4, 29=5^2+4, 53=7^2+4 are prime and 53 is the 4th such prime.

%t Table[Select[Range[0,1000]^2+n,PrimeQ][[n]],{n,40}] (* _Harvey P. Dale_, Aug 30 2016 *)

%K nonn

%O 1,1

%A _John L. Drost_, Apr 28 2007