A303839 Number of noncrossing path sets on n nodes up to rotation and reflection with each path having at least two nodes.

1, 0, 1, 1, 3, 5, 17, 40, 138, 430, 1546, 5478, 20525, 77310, 298301, 1161692, 4583525, 18239037, 73221198, 296046399, 1205038270, 4933969005, 20311807087, 84029440358, 349201537324, 1457205298510, 6104204225832, 25661191956781, 108231773165825

Offset: 0

Author

Andrew Howroyd, May 01 2018

Keywords

• nonn

Examples

			Case n=4: There are 3 possibilities:
.
   o---o   o   o   o---o
           |   |     /
   o---o   o---o   o---o
.
		

Links

• Andrew Howroyd, Table of n, a(n) for n = 0..200

Crossrefs

Cf. A303730, A303731, A303835, A303844.

Programs

PARI

\\ See A303731 for NCPathSetsModDihedral
Vec(NCPathSetsModDihedral(vector(30, k, k>1)))