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%I #8 Jan 19 2019 12:07:59
%S 4,48,384,2736,18336,118032,739008,4533744,27384288,163381968,
%T 965118720,5654345136,32898781728,190290667152,1095084877632,
%U 6274151751024,35807326610016,203653219107408,1154714957732736,6529188836867376
%N Number of n X 2 0..3 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling three exactly once.
%H R. H. Hardin, <a href="/A269180/b269180.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 10*a(n-1) - 21*a(n-2) - 20*a(n-3) - 4*a(n-4) for n>5.
%F Empirical g.f.: 4*x*(1 - x)^2*(1 + 2*x)^2 / (1 - 5*x - 2*x^2)^2. - _Colin Barker_, Jan 19 2019
%e Some solutions for n=4:
%e ..1..1. .2..3. .3..3. .1..0. .3..0. .0..2. .1..1. .2..0. .1..0. .1..1
%e ..0..0. .2..0. .1..3. .2..0. .2..2. .2..0. .1..3. .1..0. .0..0. .0..0
%e ..2..0. .2..0. .0..1. .0..0. .2..0. .1..0. .1..3. .0..0. .1..0. .1..0
%e ..3..2. .2..2. .0..1. .0..0. .2..0. .0..0. .1..0. .0..0. .3..1. .1..3
%Y Column 2 of A269186.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 20 2016
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