A316195 Number of self-avoiding polygons with perimeter 2*n and sides = 1 that have vertex angles from the set +-Pi/5, +-3*Pi/5, not counting rotations and reflections as distinct.

0, 0, 2, 1, 18, 45, 441

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..7.

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

Hugo Pfoertner, Illustration of polygons of perimeter <= 14.

Crossrefs

Cf. A306175, A258206, A266549, A284869.

Sequence in context: A300956 A089014 A063426 * A266010 A349960 A181870

Adjacent sequences: A316192 A316193 A316194 * A316196 A316197 A316198

Keyword

nonn,walk,more

Author

Hugo Pfoertner, Jun 26 2018

Status

approved