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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 3
0, 0, 0, 0, 1, 2, 12, 40, 154, 760, 3260, 22730 (list; graph; refs; listen; history; text; internal format)
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

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Last modified June 25 19:53 EDT 2017. Contains 288729 sequences.