Number of 6k+1 primes (A002476) in range ]2^n,2^(n+1)].

Terms

a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =7a(6) =11a(7) =20a(8) =37a(9) =69a(10) =126a(11) =228a(12) =434a(13) =806a(14) =1514a(15) =2845a(16) =5361a(17) =10212a(18) =19308a(19) =36747a(20) =70135a(21) =134065a(22) =256824a(23) =492871a(24) =946880a(25) =1822913a(26) =3513737a(27) =6780428a(28) =13103565a(29) =25348226