cp's OEIS Frontend

A183771 1/32 the number of (n+1) X 9 binary arrays with equal numbers of 2 X 2 subblocks with sum mod two being 0 and 1.

%I A183771 #7 Jan 14 2017 09:39:01
%S A183771 2240,823680,346131968,153876579840,70577422755840,33021546171494400,
%T A183771 15664518350357381120,7506428481300850827264,
%U A183771 3625062729947846895239168,1761398107886979915147182080,860111024347049203759900262400
%N A183771 1/32 the number of (n+1) X 9 binary arrays with equal numbers of 2 X 2 subblocks with sum mod two being 0 and 1.
%C A183771 Column 8 of A183772.
%H A183771 R. H. Hardin, <a href="/A183771/b183771.txt">Table of n, a(n) for n = 1..29</a>
%e A183771 Some solutions for 3 X 9:
%e A183771 ..0..0..0..0..0..0..0..0..0....0..0..0..0..0..0..0..0..1
%e A183771 ..0..0..1..1..0..0..0..1..0....0..1..1..1..1..0..0..1..0
%e A183771 ..0..1..0..1..1..1..0..1..0....1..0..1..0..1..0..0..0..0
%K A183771 nonn
%O A183771 1,1
%A A183771 _R. H. Hardin_, Jan 06 2011