A240123 Number of inequivalent ways to cut an n X n square into squares with integer sides, such that the dissection has a reflective symmetry in one diagonal, but no other symmetries.

0, 0, 1, 3, 19, 107, 847, 8647, 119835, 2255123, 58125783, 2050662011

Offset

1,4

Comments

'Inequivalent' has the same sense as in A224239: we do not regard dissections that differ by a rotation and/or reflection as distinct.

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 three dissections for n=4:
---------    ---------    ---------
|   | | |    |   |   |    |     | |
|   -----    |   |   |    |     ---
|   | | |    |   |   |    |     | |
---------    ---------    |     ---
| | | | |    |   | | |    |     | |
---------    |   -----    ---------
| | | | |    |   | | |    | | | | |
---------    ---------    ---------

Crossrefs

Cf. A226980, A045846, A224239, A240124, A240125.

Sequence in context: A089164 A323290 A072950 * A130425 A334976 A103005

Adjacent sequences: A240120 A240121 A240122 * A240124 A240125 A240126

Keyword

nonn,more

Author

Ed Wynn, Apr 01 2014

Status

approved