%I #7 Jan 14 2017 01:40:46
%S 10704,3333345,1339793447,586441134417,266823559411796,
%T 124201308194651058,58705095126108291860,28056029360014523631654,
%U 13521010840482176059922831,6558986191129563851102130327
%N 1/4 the number of (n+1) X 9 binary arrays with equal numbers of 2 X 2 subblocks with sums 1 and 3.
%C Column 8 of A184604.
%H R. H. Hardin, <a href="/A184603/b184603.txt">Table of n, a(n) for n = 1..19</a>
%e Some solutions for 3 X 9:
%e ..0..0..1..1..1..0..0..1..1....0..0..0..0..1..1..0..0..0
%e ..0..0..0..0..1..0..0..0..1....0..0..0..1..1..1..1..1..0
%e ..0..0..0..1..0..1..1..1..1....0..0..0..0..1..1..1..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 18 2011