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%I #7 Apr 22 2021 14:41:33
%S 8,190,4588,112750,2823604,70004726,1748785516,43705413710,
%T 1092621380500,27317384777366,682990333610700,17076690802445486,
%U 426968760440748852,10675538566342917910,266921663443974490508,6673873780235914735374
%N Number of 2n X 10 0..2 arrays with values 0..2 introduced in row major order and each element equal to exactly two horizontal and vertical neighbors.
%C Column 5 of A198285.
%H R. H. Hardin, <a href="/A198282/b198282.txt">Table of n, a(n) for n = 1..82</a>
%e Some solutions for n=3
%e ..0..0..1..1..2..2..0..0..0..0....0..0..0..0..1..1..2..2..2..2
%e ..0..0..1..1..2..2..0..2..2..0....0..2..2..0..1..1..2..0..0..2
%e ..1..1..2..2..1..1..0..2..2..0....0..2..2..0..2..2..2..0..0..2
%e ..1..1..2..2..1..1..0..0..0..0....0..1..1..0..2..0..0..2..2..2
%e ..2..2..1..1..0..0..2..2..1..1....0..1..1..0..2..0..0..2..1..1
%e ..2..2..1..1..0..0..2..2..1..1....0..0..0..0..2..2..2..2..1..1
%Y Cf. A198285.
%K nonn
%O 1,1
%A _R. H. Hardin_ Oct 23 2011
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