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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. 3
0, 0, 1, 3, 19, 107, 847, 8647, 119835, 2255123, 58125783, 2050662011 (list; graph; refs; listen; history; text; internal format)
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

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Last modified August 10 02:28 EDT 2020. Contains 336367 sequences. (Running on oeis4.)