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A126764
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Number of L-convex 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).
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2
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1, 1, 2, 6, 15, 35, 76, 156, 310, 590, 1098, 1984, 3515, 6094, 10398, 17434, 28837, 47038, 75820
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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REFERENCES
| G. Castiglione, A. Frosini, E. Munarini, A. Restivo and S. Rinaldi, Combinatorial aspects of L-convex polyominoes, to appear in European Journal of Combinatorics, 2007.
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FORMULA
| The reference gives a generating function.
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CROSSREFS
| Cf. A000105, A003480, A126765.
Sequence in context: A073838 A014303 A076060 * A090982 A153517 A136302
Adjacent sequences: A126761 A126762 A126763 * A126765 A126766 A126767
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com), based on email from Simone Rinaldi (rinaldi(AT)unisi.it), Feb 23 2007. Definition corrected at suggestion of Emeric Deutsch, Mar 03 2007
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