%I #7 Jan 14 2017 01:41:34
%S 784,60569,6045460,661355087,75369979530,8783684627835,
%T 1038876920232926,124201308194651058,14971003403040041129,
%U 1816251101842544994491,221492117754765269030948,27126817151861700072792723
%N 1/4 the number of (n+1) X 7 binary arrays with equal numbers of 2 X 2 subblocks with sums 1 and 3.
%C Column 6 of A184604.
%H R. H. Hardin, <a href="/A184601/b184601.txt">Table of n, a(n) for n = 1..50</a>
%e Some solutions for 3 X 7:
%e ..1..0..1..1..1..0..1....0..0..0..1..1..1..0....1..0..1..1..0..1..0
%e ..1..0..0..1..1..1..0....1..0..0..1..0..0..1....0..0..1..1..0..1..1
%e ..0..0..0..1..1..0..0....1..1..1..0..0..1..1....1..0..0..1..0..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 18 2011