A283106 Number of distinct envelope areas of the polyominoes of order n.

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

Author

Francois Alcover, Feb 28 2017

Keywords

• nonn

Comments

The envelope of a polyomino is the minimal rectangle containing it.

Examples

			a(3) = 2;
The two possible envelopes are
|*|
|*|
|*|    area = 3;
and
|*| |
|*|*|  area = 4.
		

Crossrefs

Cf. A071764 (distinct envelope ratios).