OFFSET
0,2
COMMENTS
Indexing starts from zero, because a(0) = 0 is a special case, indicating an empty path, which thus ends at the same vertex as where it started from.
LINKS
Antti Karttunen, Table of n, a(n) for n = 0..874
EXAMPLE
63 ("111111" in binary) is present as it encodes a single hex. This is because when we walk in honeycomb-lattice from vertex to vertex, at each vertex turning to the same direction, we will return to the starting vertex after enclosing a hex with six such steps.
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Antti Karttunen, May 16 2015
STATUS
approved