A220165 Number of nonsquare simple imperfect squared rectangles of order n up to symmetry.

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 9, 33, 104, 280, 948, 3014, 9494, 30302, 98897, 323372, 1080168, 3666666, 12604812, 43734613, 153788715

Offset

1,12

Comments

A squared rectangle is a rectangle dissected into a finite number, two or more, of squares. If no two of these squares have the same size the squared rectangle is perfect. A squared rectangle is simple if it does not contain a smaller squared rectangle. The order of a squared rectangle is the number of constituent squares.

References

See A002881 and A006983.

Links

Table of n, a(n) for n=1..26.

Stuart E. Anderson, Simple Imperfect Squared Rectangles, orders 9 to 24

Crossrefs

Cf. A002881, A006983, A002962, A002839.

Sequence in context: A048479 A031880 A231765 * A036543 A147269 A147123

Adjacent sequences: A220162 A220163 A220164 * A220166 A220167 A220168

Keyword

nonn,hard

Author

Stuart E Anderson, Dec 06 2012

Extensions

a(25) from Stuart E Anderson, May 07 2024

a(26) from Stuart E Anderson, Jul 28 2024

Status

approved