A364617 Number of tilings of a 7 X n rectangle using dominoes and trominoes (of any shape).

1, 3, 280, 17300, 1075397, 68846551, 4263997124, 267855152858, 16785795917908, 1051116421516975, 65871551452359237, 4126577980480405170, 258538236543240798654, 16197912784372244064693, 1014813990592495583029006, 63579642939479330198729573, 3983348112669764700919476270

Offset: 0

Author

Alois P. Heinz, Jul 29 2023

Keywords

• nonn

Examples

			a(1) = 3:
    ._.   ._.   ._.
    | |   | |   | |
    |_|   |_|   | |
    | |   | |   |_|
    |_|   | |   | |
    | |   |_|   |_|
    | |   | |   | |
    |_|   |_|   |_|   .
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..557
• Wikipedia, Domino (mathematics)
• Wikipedia, Tromino

Crossrefs

Column k=7 of A364457.

Extensions

Terms n>=4 had to be corrected as was pointed out by Martin Fuller and David Radcliffe - Alois P. Heinz, Apr 05 2025