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A296021 Number of primes of the form 4*k+1 <= 4*n+1. 6

%I

%S 0,1,1,2,3,3,3,4,4,5,6,6,6,7,7,8,8,8,9,9,9,9,10,10,11,12,12,13,14,14,

%T 14,14,14,14,15,15,15,16,16,17,17,17,17,18,18,19,19,19,20,21,21,21,21,

%U 21,21,21,21,22,23,23,24,24,24,24,25,25,25,26,26,27,28,28

%N Number of primes of the form 4*k+1 <= 4*n+1.

%H Seiichi Manyama, <a href="/A296021/b296021.txt">Table of n, a(n) for n = 0..10000</a>

%o (Ruby)

%o require 'prime'

%o def A(k, n)

%o ary = []

%o cnt = 0

%o k.step(4 * n + k, 4){|i|

%o cnt += 1 if i.prime?

%o ary << cnt

%o }

%o ary

%o end

%o p A(1, 100)

%Y Cf. A016813, A091098, A295996, A296020.

%K nonn

%O 0,4

%A _Seiichi Manyama_, Dec 02 2017

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Last modified October 22 16:15 EDT 2021. Contains 348174 sequences. (Running on oeis4.)