A218210 - OEIS

%I #8 Oct 23 2012 13:19:14

%S 2,3,6,10,22,53,139,369,1050,2984,8618,24390

%N Number of primes up to 10^n that are of the form (k-2)^2 + (k-1)^2 + k^2.

%C There are two primes < 10: 2 and 5.

%F a(n) = sum(A218209(k), k=1..n)

%t n = -1; cnt = 0; Do[While[n++; p = 3*n^2 + 2; p < 10^e, If[PrimeQ[p], cnt++]]; n--; cnt, {e, 10}] (* _T. D. Noe_, Oct 23 2012 *)

%Y Cf. A027863, A027864, A218208, A218209, A218212.

%K nonn,base

%O 1,1

%A _Martin Renner_, Oct 23 2012