A094165 Number of rooted 2-dimensional polyominoes with n hexagonal cells, with no symmetries removed.

1, 6, 33, 176, 930, 4884, 25564, 133512, 696231, 3626710, 18876363, 98186556, 510472118, 2652899130, 13782560610, 71585293504, 371724613716, 1929911381586, 10018066789546, 51996091023360, 269839578888159, 1400217128810676

Offset: 1

Author

N. J. A. Sloane, May 07 2004

Keywords

• nonn

References

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

Links

• Jean-François Alcover, Table of n, a(n) for n = 1..35
• R. C. Schroeppel, A few mathematical experiments, Experimental Mathematics Workshop, Oakland, 2004.

Crossrefs

A row of A094166.

Cf. A001207.

Programs

Mathematica

A001207 = Cases[Import["https://oeis.org/A001207/b001207.txt", "Table"], {, }][[All, 2]];
a[n_] := n * A001207[[n]];
Array[a, 22] (* Jean-François Alcover, Sep 08 2019 *)

Formula

a(n) = n * A001207(n). - Andrew Howroyd, Dec 04 2018