

A126764


Number of Lconvex polyominoes with n cells, that is, convex polyominoes where any two cells can be connected by a path internal to the polyomino and which has at most 1 change of direction (i.e., one of the four orientation of the letter L).


2



1, 1, 2, 6, 15, 35, 76, 156, 310, 590, 1098, 1984, 3515, 6094, 10398, 17434, 28837, 47038, 75820
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OFFSET

0,3


LINKS

Table of n, a(n) for n=0..18.
G. Castiglione, A. Frosini, E. Munarini, A. Restivo and S. Rinaldi, Combinatorial aspects of Lconvex polyominoes, European J. Combin. 28 (2007), no. 6, 17241741.


FORMULA

The reference gives a generating function.


CROSSREFS

Cf. A000105, A003480, A126765.
Sequence in context: A073838 A014303 A076060 * A272340 A090982 A153517
Adjacent sequences: A126761 A126762 A126763 * A126765 A126766 A126767


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, based on email from Simone Rinaldi (rinaldi(AT)unisi.it), Feb 23 2007


EXTENSIONS

Definition corrected at suggestion of Emeric Deutsch, Mar 03 2007


STATUS

approved



