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A221196 Number of n X 3 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, with no occupancy greater than 2.

%I A221196 #11 Aug 04 2018 06:40:53
%S A221196 2,10,46,212,976,4492,20672,95128,437752,2014400,9269632,42655888,
%T A221196 196288736,903257824,4156502752,19126892096,88015820416,405020564416,
%U A221196 1863774679808,8576493051520,39466269101440,181611106939904
%N A221196 Number of n X 3 arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, with no occupancy greater than 2.
%C A221196 Column 3 of A221200.
%H A221196 R. H. Hardin, <a href="/A221196/b221196.txt">Table of n, a(n) for n = 1..33</a>
%F A221196 Empirical: a(n) = 6*a(n-1) - 6*a(n-2) - 2*a(n-3).
%F A221196 Empirical g.f.: 2*x*(1 - x - x^2) / (1 - 6*x + 6*x^2 + 2*x^3). - _Colin Barker_, Aug 04 2018
%e A221196 Some solutions for n=3:
%e A221196 ..0..2..0....0..2..0....1..2..0....1..2..1....1..2..1....1..2..0....0..2..1
%e A221196 ..1..2..2....0..2..2....0..2..1....1..2..0....0..2..1....1..2..0....0..2..2
%e A221196 ..0..2..0....0..2..1....0..2..1....0..2..0....0..2..0....0..2..1....0..2..0
%Y A221196 Cf. A221200.
%K A221196 nonn
%O A221196 1,1
%A A221196 _R. H. Hardin_, Jan 04 2013