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 A217310 #32 Nov 25 2018 12:58:27 %S A217310 0,0,4,4,32,38,264,342,2288,3134,20740,29526,194916,285458,1885840, %T A217310 2822310,18682016,28440970,188717116,291294678,1937706144,3025232480, %U A217310 20173268632,31797822936,212530874156,337731551446,2262235585956,3620119437762,24297593488468 %N A217310 The number of meandering curves of order n, with only one extremity covered by its arcs. %C A217310 A meandering curve of order n is a continuous curve which does not intersect itself yet intersects a horizontal line n times. %D A217310 A. Panayotopoulos and P. Tsikouras, Properties of meanders, JCMCC 46 (2003), 181-190. %H A217310 Panayotis Vlamos, <a href="/A217310/b217310.txt">Table of n, a(n) for n = 1..42</a> %H A217310 A. Panayotopoulos, P. Vlamos, <a href="http://dx.doi.org/10.1007/s11786-015-0234-0">Partitioning the Meandering Curves</a>, Mathematics in Computer Science (2015) p 1-10. %F A217310 a(n) = A223093(n) * A000034(n). - _Andrew Howroyd_, Dec 06 2015 %Y A217310 Cf. A005315. %K A217310 nonn %O A217310 1,3 %A A217310 _Panayotis Vlamos_, _Antonios Panayotopoulos_, Georgia Theocharopoulou, Mar 17 2013