A217318 The number of meandering curves of order n, with both extremity covered by its arcs.

0, 0, 0, 1, 10, 20, 156, 273, 1986, 3358, 23742, 39736, 277178, 462794, 3205896, 5355743, 36963722, 61856394, 426075994, 714515312, 4916833424, 8263479072, 56840484232, 95733461792, 658460090994, 1111253958664, 7644360501390, 12925362323004, 88938175307354

Offset

1,5

Comments

A meandering curve of order n is a continuous curve which does not intersect itself yet intersects a horizontal line n times.

References

A. Panayotopoulos and P. Tsikouras, Properties of meanders, JCMCC 46 (2003), 181-190.

Links

Panayotis Vlamos, Table of n, a(n) for n = 1..42

A. Panayotopoulos, P. Vlamos, Partitioning the Meandering Curves, Mathematics in Computer Science (2015) p 1-10.

Formula

a(n) = A223095(n) * A000034(n) / 2. - Andrew Howroyd, Dec 06 2015

Crossrefs

Cf. A005315.

Sequence in context: A327971 A250107 A038693 * A239237 A018990 A280882

Adjacent sequences: A217315 A217316 A217317 * A217319 A217320 A217321

Keyword

nonn

Author

Panayotis Vlamos, Antonios Panayotopoulos, and Georgia Theocharopoulou, Mar 18 2013

Status

approved