A216598 Number of distinct connected planar figures that can be formed from n 1 X 2 rectangles (or dominoes).

1, 2, 16, 164, 1866, 22518, 282184, 3630256, 47614214, 633835642, 8537220172

Offset

0,2

Comments

"Connected" means "connected by edges".

Rotations and reflections are considered different (cf. A056786).

Internal arrangement of dominoes is significant (cf. A056785). - Aaron N. Siegel, May 22 2022

Links

Table of n, a(n) for n=0..10.

Manfred Scheucher, Sage Script.

N. J. A. Sloane, Illustration of initial terms of A056786, A216598, A216583, A216595, A216492, A216581.

N. J. A. Sloane, Illustration of third term of A056786, A216598, A216583, A216595, A216492, A216581 (a better drawing for the third term).

M. Vicher, Polyforms.

Index entries for sequences related to dominoes

Crossrefs

Cf. A056786, A216598, A216583, A216595, A216492, A216581.

Sequence in context: A374848 A326362 A287222 * A219397 A275912 A337870

Adjacent sequences: A216595 A216596 A216597 * A216599 A216600 A216601

Keyword

nonn,more,nice,hard

Author

N. J. A. Sloane, Sep 09 2012

Extensions

a(4) found via equivalence class decomposition over bounding boxes by the Forest Grove Community School Math Club - Markus J. Q. Roberts, Apr 03 2013

a(5)-a(9) from Manfred Scheucher, Jun 06 2015

a(10) from Aaron N. Siegel, May 22 2022

Status

approved