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.

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

Author

Pontus von Brömssen, Nov 18 2023

Keywords

• nonn
• tabf

Comments

Can be read as an irregular triangle, whose m-th row contains A000105(m) terms, m >= 1.

Examples

			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.
		

Links

• Pontus von Brömssen, Table of n, a(n) for n = 1..6473 (rows 1..10).
• Index entries for sequences related to polyominoes.

Crossrefs

Cf. A000105, A246521, A255890 (row minima), A367126, A367439, A367441.