login
A367439
a(n) is the degree of the polyomino with binary code A246521(n+1) in the polyomino graph PG(n) defined in A367435.
4
0, 0, 1, 1, 4, 3, 4, 3, 2, 10, 8, 3, 9, 10, 9, 8, 9, 10, 8, 4, 2, 15, 28, 15, 12, 12, 10, 17, 14, 19, 20, 15, 14, 15, 13, 18, 20, 9, 14, 13, 17, 4, 12, 16, 18, 11, 9, 10, 15, 22, 19, 10, 19, 14, 16, 3, 36, 36, 35, 31, 28, 30, 36, 22, 29, 37, 16, 11, 28, 13, 24
OFFSET
1,5
COMMENTS
Number of free polyominoes that can be made from the polyomino with binary code A246521(n+1) by moving one of its cells (not counting itself), where the intermediate (the set of cells remaining when the cell to be moved is detached) is required to be a (connected) polyomino.
Can be read as an irregular triangle, whose m-th row contains A000105(m) terms, m >= 1.
FORMULA
a(n) <= A367126(n).
EXAMPLE
As an irregular triangle:
0;
0;
1, 1;
4, 3, 4, 3, 2;
10, 8, 3, 9, 10, 9, 8, 9, 10, 8, 4, 2;
...
For n = 8, A246521(8+1) = 30 is the binary code of the S-tetromino. By moving one cell of the S-tetromino, we can obtain the L, O, and T tetrominoes (but not the I tetromino), so a(8) = 3.
CROSSREFS
Sequence in context: A106049 A367914 A238234 * A367126 A136627 A108171
KEYWORD
nonn,tabf
AUTHOR
STATUS
approved