A046677 - OEIS

%I #10 Mar 02 2015 16:08:44

%S 2,3,3,2,3,4,5,6,4,7,7,4,4,8,6,5,6,10,6,4,10,5,12,7,11,13,9,13,11,10,

%T 10,17,8,12,12,14,16,14,14,19,10,9,17,15,19,17,17,17,13,18,16,22,15,

%U 20,20,11,16,20,18,15,16,19,15,18,16,17,18,25,17,24,20,22,26,21,18,20,27

%N Number of primes p of the form p = 4m^2+1 for n^2 < m < (n+1)^2.

%D P. J. van Albada, Factorization of the numbers n^2+1, Nieuw Arch. Wisk., 16 (1998), pp. 191-197.

%t Table[Count[4 #^2 + 1 & /@ Range[n^2 + 1, (n + 1)^2 - 1], _?PrimeQ], {n, 77}] (* _Jayanta Basu_, Jun 27 2013 *)

%K nonn

%O 1,1

%A _Floor van Lamoen_