A316199 Number of self-avoiding polygons with perimeter 2*n and sides = 1 that have vertex angles from the set +-Pi/9, +-3*Pi/9, +-5*Pi/9, +-7*Pi/9, not counting rotations and reflections as distinct.

0, 0, 8, 17, 472, 7042

Offset

1,3

Comments

Holes are excluded, i.e., the boundary path may nowhere touch or intersect itself.

Links

Table of n, a(n) for n=1..6.

Contest Organizers, Al Zimmermann's Programming Contests - Snakes on a Plane, Fall 2006.

Hugo Pfoertner, Illustration of polygons of perimeter <= 12.

Crossrefs

Cf. A306179, A316195, A316197, A316198.

Sequence in context: A041126 A248289 A176823 * A300905 A008664 A107779

Adjacent sequences: A316196 A316197 A316198 * A316200 A316201 A316202

Keyword

nonn,walk,more

Author

Hugo Pfoertner, Jul 04 2018

Status

approved