a(n) = floor(n^2/Pi).

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =5a(5) =7a(6) =11a(7) =15a(8) =20a(9) =25a(10) =31a(11) =38a(12) =45a(13) =53a(14) =62a(15) =71a(16) =81a(17) =91a(18) =103a(19) =114a(20) =127a(21) =140a(22) =154a(23) =168a(24) =183a(25) =198a(26) =215a(27) =232a(28) =249a(29) =267