|
%I #6 Apr 05 2020 22:22:57
%S 16,240,3346,46126,636996,8802600,121623396,1680297950,23214121178,
%T 320714593384,4430829128772,61214050174352,845701665042092,
%U 11683776706885344,161417013884667940,2230053943181472702
%N Number of n X 4 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 5 binary array having two adjacent 1's and two adjacent 0's.
%C Column 4 of A227442.
%H R. H. Hardin, <a href="/A227440/b227440.txt">Table of n, a(n) for n = 1..52</a>
%e Some solutions for n=4
%e ..1..1..1..1....1..0..0..0....1..1..0..1....1..1..0..1....1..0..0..0
%e ..1..0..0..0....1..0..0..0....0..1..0..1....0..1..0..0....1..0..0..0
%e ..0..1..1..1....0..1..0..0....0..0..0..1....1..0..0..1....0..1..1..0
%e ..1..1..0..0....0..0..1..1....1..1..0..1....1..1..1..1....0..1..0..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Jul 11 2013
| 