Number of fixed Tangles of size n.

Terms

a(0) =1a(1) =2a(2) =6a(3) =22a(4) =88a(5) =372a(6) =1626a(7) =7292a(8) =33309a(9) =154374a(10) =723740a(11) =3425124a(12) =16336747a(13) =78437858