A365566 Triangle read by rows: T(n,d) is the number of inequivalent properly d-dimensional n-polysticks (or polyedges), 1 <= d <= n.

1, 1, 1, 1, 4, 2, 1, 15, 12, 3, 1, 54, 105, 39, 6, 1, 221, 863, 566, 117, 11

Offset: 1

Author

Pontus von Brömssen, Sep 09 2023

Keywords

• nonn
• tabl
• hard
• more

Examples

			Triangle begins:
  n\d | 1   2   3   4   5  6
  ----+---------------------
   1  | 1
   2  | 1   1
   3  | 1   4   2
   4  | 1  15  12   3
   5  | 1  54 105  39   6
   6  | 1 221 863 566 117 11
		

Links

• Index entries for sequences related to polyominoes.

Crossrefs

Cf. A000055, A049430 (polyominoes), A365565 (row sums), A385582 (fixed), A385583.

Formula

T(n,n) = A000055(n+1).

T(n,d) = A385583(n,d) - A385583(n,d-1) (with A385583(n,0) = 0). - Pontus von Brömssen, Jul 13 2025