A219861 Number of ways to dissect a nonsquare rectangle into n rectangles of equal area up to symmetry.

1, 2, 4, 11, 35, 130, 562, 2685, 13901, 76046

Offset: 1

Author

Geoffrey H. Morley, Nov 29 2012

Keywords

• nonn
• more

Examples

			There are 4 ways (up to symmetry) to form a nonsquare rectangle from 3 rectangles with the same area:
+-----+ +-+-+-+ +-----+ +-+---+
|     | | | | | |     | | |   |
+-----+ | | | | +--+--+ | |   |
|     | | | | | |  |  | | +---+
+-----+ | | | | |  |  | | |   |
|     | | | | | |  |  | | |   |
+-----+ +-+-+-+ +--+--+ +-+---+
So a(3)=4.
The eleven solutions for n=4 can be seen as a subset of the illustration of A189243(4) = 21 in that entry. - _N. J. A. Sloane_, Dec 05 2012
		

Crossrefs

Cf. A108066, A189243.

Extensions

a(7)-a(10) from Geoffrey H. Morley, Dec 16 2012