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Number of rooted 2-dimensional polyominoes with n hexagonal cells, with no symmetries removed.
2

%I #18 Sep 08 2019 11:45:32

%S 1,6,33,176,930,4884,25564,133512,696231,3626710,18876363,98186556,

%T 510472118,2652899130,13782560610,71585293504,371724613716,

%U 1929911381586,10018066789546,51996091023360,269839578888159,1400217128810676

%N Number of rooted 2-dimensional polyominoes with n hexagonal cells, with no symmetries removed.

%D Dan Hoey, Bill Gosper and Richard C. Schroeppel, Discussions in Math-Fun Mailing list, circa Jul 13 1999.

%H Jean-François Alcover, <a href="/A094165/b094165.txt">Table of n, a(n) for n = 1..35</a>

%H R. C. Schroeppel, <a href="http://www.experimentalmath.info/workshop2004/schroeppel-talk.pdf">A few mathematical experiments</a>, Experimental Mathematics Workshop, Oakland, 2004.

%F a(n) = n * A001207(n). - _Andrew Howroyd_, Dec 04 2018

%t A001207 = Cases[Import["https://oeis.org/A001207/b001207.txt", "Table"], {_, _}][[All, 2]];

%t a[n_] := n * A001207[[n]];

%t Array[a, 22] (* _Jean-François Alcover_, Sep 08 2019 *)

%Y A row of A094166.

%Y Cf. A001207.

%K nonn

%O 1,2

%A _N. J. A. Sloane_, May 07 2004