A067767 Number of alternating link diagrams with n crossings, 2 connected components and two external legs.

4, 90, 1349, 17220, 203568, 2312094, 25691670, 282000444, 3074136464, 33387698708, 361969672904, 3921901043440, 42499598861832, 460831546801414, 5001468564165262, 54341248085414380

Offset

4,1

Links

Table of n, a(n) for n=4..19.

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

A column of A062038.

Sequence in context: A337081 A218385 A189882 * A240379 A304190 A362603

Adjacent sequences: A067764 A067765 A067766 * A067768 A067769 A067770

Keyword

nonn

Author

N. J. A. Sloane, Feb 09 2002

Status

approved