Number of prime pairs {p,q}, such that pq < n^2.

Terms

a(0) =0a(1) =2a(2) =6a(3) =8a(4) =13a(5) =16a(6) =22a(7) =26a(8) =34a(9) =39a(10) =48a(11) =55a(12) =62a(13) =75a(14) =82a(15) =89a(16) =103a(17) =113a(18) =126a(19) =135a(20) =149a(21) =163a(22) =179a(23) =190a(24) =202a(25) =220a(26) =236a(27) =252a(28) =270a(29) =288