Number of oriented prime alternating tangles.

Terms

a(0) =1a(1) =2a(2) =7a(3) =29a(4) =137a(5) =679a(6) =3515a(7) =18677a(8) =101463a(9) =560062a(10) =3132639a(11) =17708417a(12) =100998567a(13) =5803646663a(14) =3356435363a(15) =19519575163