A240124 Number of inequivalent ways to cut an n X n square into squares with integer sides, such that the dissection has 180-degree rotational symmetry, but no other symmetries.

0, 0, 0, 0, 2, 19, 109, 1781, 13660, 397689, 5368943, 289864745

Offset

1,5

Links

Table of n, a(n) for n=1..12.

Ed Wynn, Exhaustive generation of Mrs Perkins's quilt square dissections for low orders, arXiv:1308.5420

Example

The two dissections for n=5:
-----------    -----------
|   |   | |    | |   | | |
|   |   ---    ---   -----
|   |   | |    | |   | | |
-----------    -----------
| | | | | |    | | | | | |
-----------    -----------
| |   |   |    | | |   | |
---   |   |    -----   ---
| |   |   |    | | |   | |
-----------    -----------

Crossrefs

Cf. A226980, A045846, A224239, A240123, A240125.

Sequence in context: A193047 A055875 A089659 * A278405 A285791 A101253

Adjacent sequences: A240121 A240122 A240123 * A240125 A240126 A240127

Keyword

nonn,more

Author

Ed Wynn, Apr 01 2014

Status

approved