Number of 4k+3 primes (A002145) in range ]2^n,2^(n+1)].

Terms

a(0) =1a(1) =1a(2) =1a(3) =3a(4) =3a(5) =7a(6) =13a(7) =22a(8) =37a(9) =71a(10) =128a(11) =231a(12) =440a(13) =807a(14) =1519a(15) =2872a(16) =5371a(17) =10204a(18) =19341a(19) =36759a(20) =70179a(21) =134241a(22) =256856a(23) =492936a(24) =947272a(25) =1822615a(26) =3513691a(27) =6781495a(28) =13103816a(29) =25348667