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%I #8 Jan 19 2019 12:07:24
%S 16,108,708,4476,27684,168252,1008804,5983164,35170980,205214268,
%T 1189853604,6861684156,39384946596,225136169532,1282284719268,
%U 7279841963964,41210177357988,232678853273148,1310648830057380
%N Number of n X 2 0..3 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling three no more than once.
%H R. H. Hardin, <a href="/A269188/b269188.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*(4 - 13*x - 9*x^2 - 4*x^3 + 4*x^4) / (1 - 5*x - 2*x^2)^2. - _Colin Barker_, Jan 19 2019
%e Some solutions for n=4:
%e ..0..0. .2..0. .2..2. .1..3. .3..2. .1..3. .2..2. .0..2. .3..2. .0..0
%e ..1..1. .2..2. .3..0. .3..2. .2..3. .1..0. .0..3. .0..1. .1..3. .1..2
%e ..1..0. .2..2. .1..1. .2..3. .2..2. .0..0. .1..1. .0..0. .1..1. .3..3
%e ..2..0. .0..0. .1..0. .2..3. .0..2. .2..2. .3..3. .1..0. .3..3. .1..1
%Y Column 2 of A269194.
%K nonn
%O 1,1
%A _R. H. Hardin_, Feb 20 2016
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