A306180 - OEIS

A306180

Number of unrooted self-avoiding walks with n steps that can make turns from the set 0, +-Pi/5, +-2*Pi/5, +-3*Pi/5, +-4*Pi/5.

1, 5, 23, 169, 1233, 9551

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

The turning angles are those of the regular decagon, with one vertex corresponding to the forbidden U-turn. The path may neither intersect nor touch itself anywhere.

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 walks of lengths <= 3.

CROSSREFS

Cf. A266925, A037245, A306175, A151541, A306177, A306178, A306179, A306181, A306182.

Sequence in context: A178383 A377584 A167576 * A308443 A116151 A371651

Adjacent sequences: A306177 A306178 A306179 * A306181 A306182 A306183

KEYWORD

nonn,walk,more

AUTHOR

Hugo Pfoertner, Jun 23 2018

STATUS

approved