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Number of nX1 0..3 arrays with no more than floor(nX1/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..3 order
5

%I #5 Feb 17 2013 17:05:43

%S 1,1,1,4,5,14,17,75,95,411,519,2522,3211,15919,20299,103627,132515,

%T 683480,875491,4554799,5844093,30542304,39239961,205785953,264702489,

%U 1391485044,1791699029,9436529666,12161620195,64150640719,82742154707

%N Number of nX1 0..3 arrays with no more than floor(nX1/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..3 order

%C Column 1 of A222378

%H R. H. Hardin, <a href="/A222372/b222372.txt">Table of n, a(n) for n = 1..210</a>

%e All solutions for n=4

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

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

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

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

%K nonn

%O 1,4

%A _R. H. Hardin_ Feb 17 2013