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 A046722 #25 Jul 15 2019 04:59:18 %S A046722 1,3,11,37,126,430,1454,4976,16880,57824,197010,675428,2310268, %T A046722 7927778,27205180,93448486,321537086,1105589516,3812424912, %U A046722 13121988240,45330375774,156172996170,540314673678,1863197292582,6454265995454,22275589419432,77246945788890,266813803179348 %N A046722 Number of semi-meanders of order n with 3 components. %H A046722 Andrew Howroyd, <a href="/A046722/b046722.txt">Table of n, a(n) for n = 3..40</a> %H A046722 P. Di Francesco, O. Golinelli, and E. Guitter, <a href="https://arxiv.org/abs/hep-th/9506030">Meander, folding and arch statistics</a>, arXiv:hep-th/9506030, 1995. %H A046722 P. Di Francesco, O. Golinelli, and E. Guitter, <a href="https://doi.org/10.1016/S0895-7177(97)00202-1">Meander, folding and arch statistics</a>, Mathematical and Computer Modelling 26 (1997), 97-147. %Y A046722 Cf. A000682, A046726. %K A046722 nonn %O A046722 3,2 %A A046722 _N. J. A. Sloane_ %E A046722 a(15)-a(30) from _Andrew Howroyd_, Nov 27 2015