A348196 - OEIS

%I #13 Oct 07 2021 07:22:50

%S 0,0,1,2,3,4,6,8,9,11,14,15,17,20,21,24,28,31,34,37,41,44,46,49,54,58,

%T 61,66,70,74,78,83,87,93,98,103,107,112,116,119,126,133,136,143,148,

%U 154,159,167,175,180,184,192,201,207,212,219,226,232,240,247,255,262,268,276,283,292,300,307,314,322,331,336,346,354

%N Number of primes of the form 4k+1 < n^2.

%H Seiichi Manyama, <a href="/A348196/b348196.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A066339(n^2).

%o (PARI) a(n) = sum(k=2, n^2-1, isprime(k)&&k%4==1);

%Y Cf. A066339, A348193, A348195.

%K nonn

%O 1,4

%A _Seiichi Manyama_, Oct 06 2021