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A367443
a(n) is the number of free polyominoes that can be obtained from the polyomino with binary code A246521(n+1) by adding one cell.
6
1, 2, 4, 3, 9, 1, 5, 4, 3, 8, 6, 5, 11, 10, 10, 6, 6, 9, 5, 2, 4, 5, 11, 13, 11, 3, 12, 9, 11, 10, 11, 5, 11, 5, 11, 12, 11, 12, 5, 6, 10, 5, 13, 12, 12, 7, 6, 6, 7, 11, 11, 6, 11, 6, 5, 4, 12, 11, 11, 13, 12, 11, 12, 14, 13, 12, 6, 7, 11, 3, 11, 11, 10, 11
OFFSET
1,2
COMMENTS
Can be read as an irregular triangle, whose m-th row contains A000105(m) terms, m >= 1.
EXAMPLE
As an irregular triangle:
1;
2;
4, 3;
9, 1, 5, 4, 3;
8, 6, 5, 11, 10, 10, 6, 6, 9, 5, 2, 4;
...
For n = 5, the L tetromino, whose binary code is A246521(5+1) = 15, can be extended to 9 different free pentominoes, so a(5) = 9. (All possible ways to add one cell lead to different pentominoes.)
For n = 6, the square tetromino, whose binary code is A246521(6+1) = 23, can only be extended to the P pentomino by adding one cell, so a(6) = 1.
CROSSREFS
Cf. A000105, A246521, A255890 (row minima), A367126, A367439, A367441.
Sequence in context: A253791 A021045 A272471 * A155749 A198931 A344425
KEYWORD
nonn,tabf
AUTHOR
STATUS
approved