Number of rational knots (or two-bridge knots) with n crossings (chiral pairs counted as distinct).

Terms

a(0) =0a(1) =2a(2) =1a(3) =4a(4) =5a(5) =14a(6) =21a(7) =48a(8) =85a(9) =182a(10) =341a(11) =704a(12) =1365a(13) =2774a(14) =5461a(15) =11008a(16) =21845a(17) =43862a(18) =87381a(19) =175104a(20) =349525a(21) =699734a(22) =1398101a(23) =2797568a(24) =5592405a(25) =11187542a(26) =22369621a(27) =44744704a(28) =89478485a(29) =178967894