A221841 Number of ways to dissect a square into n squares up to symmetry.

1, 0, 0, 1, 0, 1, 2, 6, 16, 56, 183, 657, 2277, 8813, 34178, 137578, 558734, 2285694

Offset

1,7

Links

Table of n, a(n) for n=1..18.

Ed Wynn, Exhaustive generation of Mrs Perkins's quilt square dissections for low orders, 2013, arXiv:1308.5420

Example

For n = 7 there are a(7) = 2 ways:
+---+---+   +---+---+
|   |   |   |   |   |
|   |   |   |   |   |
|   |   |   |   |   |
+-+-+-+-+   +---+-+-+
| |   | |   |   | | |
+-+   +-+   |   +-+-+
| |   | |   |   | | |
+-+---+-+   +---+-+-+

Crossrefs

Cf. A221840, A221842.

Sequence in context: A320805 A354083 A150029 * A068787 A073959 A006820

Adjacent sequences: A221838 A221839 A221840 * A221842 A221843 A221844

Keyword

nonn,nice,more

Author

Geoffrey H. Morley, Jan 26 2013

Extensions

a(10) corrected (thanks to Ed Wynn) by Geoffrey H. Morley, Aug 02 2013

More terms from Wynn, 2013. - N. J. A. Sloane, Nov 29 2013

Status

approved