A219994 Number of tilings of an n X n square using dominoes and right trominoes.

1, 0, 2, 8, 380, 21272, 5350806, 3238675344, 6652506271144, 38896105985522272, 711716770252031164458, 38776997923112110535353528, 6460929292946758939597712150496, 3245656750963660788826395580466708824, 4953412325525289651086730443567098343730966, 22873302288206466754758793232467436030071524731072

Offset: 0

Author

Alois P. Heinz, Dec 02 2012

Keywords

• nonn

Examples

			a(3) = 8, because there are 8 tilings of a 3 X 3 square using dominoes and right trominoes:
  .___._.   .___._.   .___._.   .___._.
  |___| |   |___| |   |___| |   |_. | |
  | ._|_|   | | |_|   | |___|   | |_|_|
  |_|___|   |_|___|   |_|___|   |_|___|
  ._.___.   ._.___.   ._.___.   ._.___.
  | |___|   | | ._|   | |___|   | |___|
  |___| |   |_|_| |   |_|_. |   |_| | |
  |___|_|   |___|_|   |___|_|   |___|_|  .
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..17
• 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 A219987.

Cf. A233807, A364504.