Number of oriented rational links with crossing number n.

Terms

a(0) =2a(1) =2a(2) =5a(3) =6a(4) =15a(5) =24a(6) =51a(7) =90a(8) =187a(9) =352a(10) =715a(11) =1386a(12) =2795a(13) =5504a(14) =11051a(15) =21930a(16) =43947a(17) =87552a(18) =175275a(19) =349866a(20) =700075a(21) =1398784a(22) =2798251a(23) =5593770a(24) =11188907a(25) =22372352a(26) =44747435a(27) =89483946a(28) =178973355a(29) =357924864