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Number of nX2 0..2 arrays with exactly floor(nX2/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..2 order
2

%I #5 Feb 19 2013 03:25:50

%S 0,0,4,13,36,132,584,2054,7700,29208,113024,428784,1637248,6322400,

%T 24241600,93878180,360819968,1402924464,5410402304,21069262688,

%U 81508818720,317854067456,1233012730240,4813042237968,18714480000512

%N Number of nX2 0..2 arrays with exactly floor(nX2/2) elements unequal to at least one horizontal or vertical neighbor, with new values introduced in row major 0..2 order

%C Column 2 of A222430

%H R. H. Hardin, <a href="/A222425/b222425.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=4

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

%e ..0..0....1..0....0..0....2..2....1..0....1..1....0..1....0..0....0..0....0..0

%e ..0..1....1..1....1..1....2..2....0..0....1..1....1..1....1..0....1..0....0..1

%e ..0..0....1..1....1..1....2..2....0..0....1..1....1..1....0..0....1..1....1..1

%K nonn

%O 1,3

%A _R. H. Hardin_ Feb 19 2013