A067645 Number of prime alternating tangles (or knots) of type Gamma_2 with two connected components.

0, 1, 1, 3, 9, 21, 101, 346, 1576, 7040, 31556, 153916, 724758, 3610768, 17853814, 90220450, 460221672, 2365627740, 12300901598

Offset

0,4

Links

Table of n, a(n) for n=0..18.

J. L. Jacobsen and P. Zinn-Justin, A Transfer Matrix approach to the Enumeration of Knots

J. L. Jacobsen and P. Zinn-Justin, A Transfer Matrix approach to the Enumeration of Colored Links, J. Knot Theory, 10 (2001), 1233-1267.

Crossrefs

Cf. A067644, A067646.

Sequence in context: A146909 A146248 A074000 * A101474 A298836 A252284

Adjacent sequences: A067642 A067643 A067644 * A067646 A067647 A067648

Keyword

nonn

Author

N. J. A. Sloane, Feb 05 2002

Status

approved