A184461 - OEIS

%I #7 Jan 15 2022 21:38:47

%S 26,244,3090,42874,616534,9016218,133687638,2002023718,30215911640,

%T 458822048550,7001737409868,107286031628502,1649589497350886,

%U 25437988001627234,393268526198504728,6093317202558667778

%N Half the number of (n+1) X 4 binary arrays with equal numbers of majority one 2 X 2 subblocks and majority zero 2 X 2 subblocks.

%C Column 3 of A184467.

%H R. H. Hardin, <a href="/A184461/b184461.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for 3 X 4

%e ..0..1..1..1....0..1..1..1....0..0..1..0....0..0..1..1....0..0..1..0

%e ..0..0..0..1....1..0..0..1....1..1..1..0....1..0..1..0....0..1..0..1

%e ..0..1..1..1....1..1..0..0....0..0..0..0....1..1..0..0....1..0..1..1

%e ...

%e ...M..E..P.......E..E..P.......E..P..E.......M..E..P.......M..E..E...

%e ...M..E..P.......P..M..M.......E..E..M.......P..E..M.......E..E..P...

%Y Cf. A184467.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 15 2011