A240124 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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:

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--- | | ----- ---

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CROSSREFS

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

Sequence in context: A193047 A055875 A089659 * A278405 A285791 A376481

Adjacent sequences: A240121 A240122 A240123 * A240125 A240126 A240127

KEYWORD

nonn,more

AUTHOR

Ed Wynn, Apr 01 2014

STATUS

approved