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Number of n X 2 arrays of occupancy after each element stays put or moves to some king-move neighbor, with no occupancy greater than 2.
1

%I #10 Aug 04 2018 14:33:03

%S 3,19,141,1073,8203,62771,480437,3677345,28147315,215447091,

%T 1649090685,12622590641,96616760123,739531104531,5660573328101,

%U 43327576375905,331641119361379,2538471829096403,19430157634105069,148723740543110065

%N Number of n X 2 arrays of occupancy after each element stays put or moves to some king-move neighbor, with no occupancy greater than 2.

%C Column 2 of A221269.

%H R. H. Hardin, <a href="/A221266/b221266.txt">Table of n, a(n) for n = 1..66</a>

%F Empirical: a(n) = 10*a(n-1) - 19*a(n-2) + 8*a(n-3).

%F Empirical g.f.: x*(1 - x)*(3 - 8*x) / (1 - 10*x + 19*x^2 - 8*x^3). - _Colin Barker_, Aug 04 2018

%e Some solutions for n=3:

%e 0 2 2 1 1 2 2 0 0 2 1 2 0 2 1 2 2 0 1 1

%e 2 0 0 0 0 1 2 1 0 2 1 0 1 1 1 0 2 2 1 0

%e 1 1 1 2 0 2 1 0 2 0 2 0 0 2 1 1 0 0 2 1

%Y Cf. A221269.

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 08 2013