%I #7 Jan 14 2017 01:43:09

%S 16,156,1986,28192,411825,6045460,89538170,1339793447,20215904926,

%T 306972320468,4684471214542,71777709052696,1103593885196101,

%U 17017816693554841,263086943851348011,4076187315351054647

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

%C Column 3 of A184604.

%H R. H. Hardin, <a href="/A184598/b184598.txt">Table of n, a(n) for n = 1..200</a>

%e Some solutions for 3 X 4:

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 18 2011