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

0,3

Links

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

Example

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

Crossrefs

Main diagonal of A219987.

Cf. A233807, A364504.

Sequence in context: A009836 A012342 A012348 * A014185 A367998 A009808

Adjacent sequences: A219991 A219992 A219993 * A219995 A219996 A219997

Keyword

nonn

Author

Alois P. Heinz, Dec 02 2012

Status

approved