A377593 Number of aligned fixed polyominoes that will fit in a square of size n X n.

1, 8, 151, 9472, 2081051, 1643823600, 4742607132499, 50303895480064088, 1966122506151835674303, 283294196554063138439927568, 150432366492029200690537003170367, 294212995394376069103067524948055548348, 2117957146063247996594586658579155551318256103, 56084287855193446153928896349599388059636859288133588, 5460061052459125116800111315595463810654508452342242195388707

Offset: 1

Author

John Mason, Nov 02 2024

Keywords

• nonn

Comments

a(n) is the number of fixed polyominoes that have both width and height <= n. The word "aligned" in the title refers to the restriction that the polyominoes have edges parallel to the sides of the square.

Examples

			a(2) = 8 because of the monomino, 2 alignments of the domino, 4 alignments of the L-shaped tromino, and the square tetromino.
		

Crossrefs

Cf. A292357, A268416, A268404.

Formula

a(n) = Sum_{i=1..n,j=1..n} A292357(i,j).