A268416 Number of aligned free polyominoes that will fit in a square of size n X n.

1, 4, 35, 1280, 262292, 205515653, 592830103236

Offset: 1

Author

John Mason, Feb 04 2016

Keywords

• nonn
• more

Comments

a(n) is the number of free polyominoes that have both width and height <= n. Compare this to Craig Knecht's A268311 which has both height and width = n. The word "aligned" in the title refers to the restriction that the polyominoes have edges parallel to the sides of the square, in contrast with A268427.

Crossrefs

Cf. A268311, A268371, A268427.

Formula

a(n) = Sum_{i=1..n*(n+1)/2} A268371(i). - John Mason, Sep 11 2024

Extensions

a(6) from Talmon Silver, Jul 29 2020

a(7) from John Mason, Sep 11 2024