A184596 - OEIS

%I #7 Jan 14 2017 01:45:47

%S 2,5,16,58,214,784,2880,10704,40264,152728,582424,2229856,8566528,

%T 33011680,127553920,493989568,1916920384,7451582080,29011376256,

%U 113108257920,441536615296,1725575305600,6750738252160,26435046548992

%N 1/4 the number of (n+1) X 2 binary arrays with equal numbers of 2 X 2 subblocks with sums 1 and 3.

%C Column 1 of A184604.

%H R. H. Hardin, <a href="/A184596/b184596.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for 3 X 2:

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 18 2011