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A216595 Number of distinct connected planar figures that can be formed from 1 X 2 rectangles (or dominoes) such that each pair of touching rectangles shares exactly one edge, of length 1. 6
1, 2, 14, 126, 1267, 13550, 150665 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,2
COMMENTS
Figures that differ by a rotation or reflection are regarded as distinct (cf. A216583).
This sequence is A216581 without the condition that the adjacency graph of the dominoes forms a tree.
An example: The two solutions
V H -
| V
H - |
and
H - V
V |
| H -
are considered to be the same because the resulting shape is the same.
LINKS
Manfred Scheucher, Python Script
N. J. A. Sloane, Illustration of third term of A056786, A216598, A216583, A216595, A216492, A216581 (a better drawing for the third term)
M. Vicher, Polyforms
CROSSREFS
Sequence in context: A060468 A349261 A121082 * A155650 A331397 A363983
KEYWORD
nonn,more
AUTHOR
N. J. A. Sloane, Sep 08 2012
EXTENSIONS
Terms a(4)-a(6) added by César Eliud Lozada, Sep 09 2012
STATUS
approved

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Last modified February 26 21:28 EST 2024. Contains 370352 sequences. (Running on oeis4.)