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 A066931 Number of ways to tile hexagon of edge n with diamonds of side 1, not counting rotations and reflections as different. 2

%I

%S 1,1,6,113,20174,22306955,123222909271,3283834214485890,

%T 421263391026827547540,260028731850596651411721718,

%U 772086476515163830856527013278243,11025620741283840573496993339545350520150,757129347300072898736973484532998417574513923224

%N Number of ways to tile hexagon of edge n with diamonds of side 1, not counting rotations and reflections as different.

%H R. K. Guy and D. J. Reble, <a href="/A066931/a066931.txt">Illustration of initial terms</a>

%H P. J. Taylor, <a href="http://cheddarmonk.org/papers/distinct-dimer-hex-tilings.pdf">Counting distinct dimer hex tilings</a>, Preprint, 2015.

%F From _Peter J. Taylor_, Jun 17 2015: (Start)

%F For odd n, a(n) = A008793(n)/12 + A049505(n)/4 + A006366(n)/6.

%F For even n, a(n) = A008793(n)/12 + A049505(n)/4 + A006366(n)/6 + A181119(n/2)/4 + A259049(n/2)/12 + A049503(n/2)/6.

%F (End)

%Y Cf. A008793.

%K nonn

%O 0,3

%A _R. K. Guy_, Feb 05 2002

%E One more term from _Don Reble_, Feb 07 2002

%E More terms from _Peter J. Taylor_, Jun 17 2015

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Last modified June 25 04:01 EDT 2021. Contains 345450 sequences. (Running on oeis4.)