cp's OEIS Frontend

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

%I A219861 #16 Dec 17 2012 18:24:15
%S A219861 1,2,4,11,35,130,562,2685,13901,76046
%N A219861 Number of ways to dissect a nonsquare rectangle into n rectangles of equal area up to symmetry.
%e A219861 There are 4 ways (up to symmetry) to form a nonsquare rectangle from 3 rectangles with the same area:
%e A219861 +-----+ +-+-+-+ +-----+ +-+---+
%e A219861 |     | | | | | |     | | |   |
%e A219861 +-----+ | | | | +--+--+ | |   |
%e A219861 |     | | | | | |  |  | | +---+
%e A219861 +-----+ | | | | |  |  | | |   |
%e A219861 |     | | | | | |  |  | | |   |
%e A219861 +-----+ +-+-+-+ +--+--+ +-+---+
%e A219861 So a(3)=4.
%e A219861 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
%Y A219861 Cf. A108066, A189243.
%K A219861 nonn,more
%O A219861 1,2
%A A219861 _Geoffrey H. Morley_, Nov 29 2012
%E A219861 a(7)-a(10) from _Geoffrey H. Morley_, Dec 16 2012