This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A067648 #3 Mar 30 2012 16:49:18 %S A067648 0,2,0,2,4,12,60,226,1076,5156,24984,128548,663040,3514968,18918792, %T A067648 103123906,569877652,3180066004,17921451960,101842206548,583109887600, %U A067648 3361640932872,19499226668816 %N A067648 Number of knot diagrams of type 2PI with n crossings and two outgoing strings. %H A067648 J. L. Jacobsen and P. Zinn-Justin, <a href="http://arXiv.org/abs/math-ph/0102015">A Transfer Matrix approach to the Enumeration of Knots</a> %Y A067648 Cf. A054993, A067647. %K A067648 nonn %O A067648 0,2 %A A067648 _N. J. A. Sloane_, Feb 05 2002 %E A067648 Reference gives two further terms.