A067647 Number of knot diagrams of type 1PI with n crossings and two outgoing strings.

0, 2, 4, 18, 108, 748, 5648, 45234, 378300, 3271204, 29049824, 263656356, 2436827328, 22871937208, 217536523260, 2092958991474, 20341256951692, 199471121367508, 1971730006936240, 19630246152650228

Offset: 0

Author

N. J. A. Sloane, Feb 05 2002

Keywords

• nonn

Links

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

Crossrefs

Cf. A054993, A067648.

Extensions

Reference gives two further terms.