A240122 Number of inequivalent ways to cut an n X n square into squares with integer sides, such that the dissection has 90-degree rotational symmetry and no reflective symmetry

0, 0, 0, 0, 1, 2, 12, 40, 154, 760, 3260, 22730

Offset

1,6

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=6:
-------------    -------------
| |   | | | |    | |   | | | |
---   -------    ---   -------
| |   | |   |    | |   | |   |
---------   |    ---------   |
| | |   |   |    | | | | |   |
-----   -----    -------------
|   |   | | |    |   | | | | |
|   ---------        ---------
|   | |   | |    |   | |   | |
-------   ---    -------   ---
| | | |   | |    | | | |   | |
-------------    -------------

Crossrefs

Cf. A226979, A045846, A224239, A240120, A240121.

Sequence in context: A212874 A074447 A190064 * A110953 A003683 A188572

Adjacent sequences: A240119 A240120 A240121 * A240123 A240124 A240125

Keyword

nonn,more

Author

Ed Wynn, Apr 01 2014

Status

approved