cp's OEIS Frontend

A316201 Number of self-avoiding polygons with perimeter 2*n and sides = 1 that have vertex angles from the set +-Pi/11, +-3*Pi/11, +-5*Pi/11, +-7*Pi/11, +-9*Pi/11, not counting rotations and reflections as distinct.

%I A316201 #7 Jul 07 2018 19:29:44
%S A316201 0,0,8,19,720,10578
%N A316201 Number of self-avoiding polygons with perimeter 2*n and sides = 1 that have vertex angles from the set +-Pi/11, +-3*Pi/11, +-5*Pi/11, +-7*Pi/11, +-9*Pi/11, not counting rotations and reflections as distinct.
%C A316201 Holes are excluded, i.e., the boundary path may nowhere touch or intersect itself.
%H A316201 Contest Organizers, <a href="http://www.recmath.org/contest/Snakes/index.php">Al Zimmermann's Programming Contests - Snakes on a Plane</a>, Fall 2006.
%H A316201 Hugo Pfoertner, <a href="http://www.randomwalk.de/sequences/a316201.htm">Illustration of polygons of perimeter <= 10</a>.
%Y A316201 Cf. A258206, A266549, A284869, A306181, A316192, A316195, A316197, A316198, A316199, A316200.
%K A316201 nonn,more
%O A316201 1,3
%A A316201 _Hugo Pfoertner_, Jul 07 2018