A056785 Number of polydominoes.

1, 4, 23, 211, 2227, 25824, 310242, 3818983, 47752136, 604425323

Offset: 1

Author

James Sellers, Aug 28 2000

Keywords

• hard
• more
• nonn
• changed

Comments

From Vicher's table.

This gives the number of polyominoes of order 2n that can be tiled by dominoes in at least one way. - Joseph Myers, Jun 10 2012

Links

• M. Keller, Counting Polyforms
• Arthur O'Dwyer, Counting polybar polyominoes, (2025).
• Herman Tulleken, Polyominoes 2.2: How they fit together, (2019).
• M. Vicher, Polyforms
• Index entries for sequences related to dominoes

Crossrefs

Cf. A056786, A213376, A213377, A213378.

Formula

a(n) + A213376(n) = A210996(n). - R. J. Mathar, Jan 30 2023

Extensions

Edited by T. D. Noe, Apr 09 2009

Offset corrected and a(6)-a(9) added by Joseph Myers, Jun 10 2012

a(10) added by Arthur O'Dwyer, Aug 28 2025