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%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