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A303839
Number of noncrossing path sets on n nodes up to rotation and reflection with each path having at least two nodes.
6
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
0,5
LINKS
EXAMPLE
Case n=4: There are 3 possibilities:
.
o---o o o o---o
| | /
o---o o---o o---o
.
PROG
(PARI) \\ See A303731 for NCPathSetsModDihedral
Vec(NCPathSetsModDihedral(vector(30, k, k>1)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Andrew Howroyd, May 01 2018
STATUS
approved