A220061 Number of tilings of an n X n square using right trominoes and 1 X 1 tiles.

1, 1, 5, 39, 2023, 249651, 128938297, 207866584389, 1208344842789831, 23649239068131551559, 1609120545126107661426575, 375082120094104660413783094451, 301522432794951154854984388046484015, 833441700776362178606942848178200903068675, 7931715551857283775957120938092133944383839378911

Offset: 0

Author

Alois P. Heinz, Dec 03 2012

Keywords

• nonn

Examples

			a(2) = 5, because there are 5 tilings of a 2 X 2 square using right trominoes and 1 X 1 tiles:
  ._._.   ._._.   .___.   .___.   ._._.
  |_|_|   | |_|   | ._|   |_. |   |_| |
  |_|_|   |___|   |_|_|   |_|_|   |___|
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..16
• Kai Liang, Solving tiling enumeration problems by tensor network contractions, arXiv:2503.17698 [math.CO], 2025. See p. 25, Table 4.

Crossrefs

Main diagonal of A220054.

Cf. A233807.