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A283106
Number of distinct envelope areas of the polyominoes of order n.
0
1, 1, 1, 2, 2, 4, 5, 7, 9, 11, 12, 16, 18, 22, 26, 30, 33, 37, 41, 47, 52, 58, 62, 69, 74, 80, 86, 92, 97, 106, 112, 120, 127, 135, 143, 152, 159, 168, 176, 186, 193, 205, 213, 225, 235, 246, 256, 269, 281, 291, 302
OFFSET
0,4
COMMENTS
The envelope of a polyomino is the minimal rectangle containing it.
EXAMPLE
a(3) = 2;
The two possible envelopes are
|*|
|*|
|*| area = 3;
and
|*| |
|*|*| area = 4.
CROSSREFS
Cf. A071764 (distinct envelope ratios).
Sequence in context: A241410 A324753 A374020 * A030769 A030739 A211861
KEYWORD
nonn
AUTHOR
Francois Alcover, Feb 28 2017
STATUS
approved