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A219861 Number of ways to dissect a nonsquare rectangle into n rectangles of equal area up to symmetry. 2
1, 2, 4, 11, 35, 130, 562, 2685, 13901, 76046 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

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.

Sequence in context: A186998 A243788 A245465 * A193058 A179379 A086611

Adjacent sequences:  A219858 A219859 A219860 * A219862 A219863 A219864

KEYWORD

nonn,more

AUTHOR

Geoffrey H. Morley, Nov 29 2012

EXTENSIONS

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

STATUS

approved

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Last modified June 19 23:01 EDT 2019. Contains 324222 sequences. (Running on oeis4.)