A341219 Number of well-connected free polyominoes with n cells, where a polyomino is defined as well-connected if, for all the squares it contains, the removal of that single square would result in an intact polyomino.
1, 1, 1, 0, 1, 0, 1, 0, 3, 1, 6, 2, 25, 18, 88
Offset: 0
Examples
a(4) = 1 because the 2 X 2 square polyomino is the only tetromino to be well-connected. The removal of any single square always results in an intact tromino. In each of the other 4 tetrominoes, there is a square whose removal would result in something that is not an intact polyomino.
Links
- John Mason, Well connected polyominoes
Crossrefs
Cf. A000105.
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