A183766 - OEIS

%I #7 Jan 14 2017 01:53:33

%S 40,7392,1555840,346131968,79420170240,18585877094400,

%T 4409408507412480,1056689477487820800,255189244398549336064,

%U 62004700939478066266112,15140238779254079729172480,3712064235466595220724908032

%N 1/32 the number of (2n+1) X 4 binary arrays with equal numbers of 2 X 2 subblocks with sum mod two being 0 and 1.

%C Column 3 of A183772(2n).

%H Ron Hardin, <a href="/A183766/b183766.txt">Table of n, a(n) for n = 1..100</a>

%e Some solutions for 3 X 4:

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 06 2011