%I #12 Jul 06 2015 23:40:51

%S 0,63,990,3822,15222,15738,15804,60858,62394,62940,224694,241110,

%T 241338,243162,243420,244188,249306,249318,249564,249660,251370,

%U 251628,251634,252396,252660,252792,964314,964326,965340,972522,972636,973548,976620,990678,995034,995046,997098,997212,998124,998130,1003242,1005420

%N Capless binary boundary codes for holeless strictly non-overlapping polyhexes, only the maximal representative from each equivalence class obtained by rotating.

%C 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.

%H Antti Karttunen, <a href="/A258004/b258004.txt">Table of n, a(n) for n = 0..874</a>

%F a(n) = A053645(A258003(n)).

%e 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.

%o (Scheme)

%o (define (A258004 n) (A053645 (A258003 n)))

%Y Cf. A053645, A258003.

%Y Subsequence of A255561 and A258014.

%K nonn,base

%O 0,2

%A _Antti Karttunen_, May 16 2015