%I #5 Mar 31 2012 12:36:34
%S 1,3,13,65,401,2798,21243,170477,1414186,11959573,102256003,879709138,
%T 7594221063,65683697809,568711886538,4926993076641,42698505718759,
%U 370102007685234,3208288130917763,27813084430989669,241122723310051914
%N Number of nX2 0..4 arrays with values 0..4 introduced in row major order and each element equal to one or two horizontal and vertical neighbors
%C Column 2 of A198669
%H R. H. Hardin, <a href="/A198663/b198663.txt">Table of n, a(n) for n = 1..200</a>
%F Empirical: a(n) = 12*a(n-1) -18*a(n-2) -96*a(n-3) -43*a(n-4) +384*a(n-5) +1030*a(n-6) +276*a(n-7) -1609*a(n-8) -3144*a(n-9) -1688*a(n-10) +1080*a(n-11) +1536*a(n-12) +768*a(n-13) -512*a(n-14) for n>16
%e Some solutions with all values 0 to 4 for n=6
%e ..0..0....0..1....0..1....0..0....0..0....0..0....0..0....0..1....0..0....0..1
%e ..1..2....0..1....0..1....1..1....1..1....1..2....1..1....0..1....1..0....0..1
%e ..1..2....1..1....2..1....2..3....2..2....1..2....2..2....2..3....1..2....2..3
%e ..3..3....2..2....2..2....2..3....3..3....3..0....3..4....2..3....3..2....2..3
%e ..1..1....3..3....3..4....1..4....3..3....3..0....3..4....3..4....3..3....4..2
%e ..4..4....4..4....3..4....1..4....4..4....4..4....4..4....3..4....4..4....4..2
%K nonn
%O 1,2
%A _R. H. Hardin_ Oct 28 2011
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