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A275143 Number of 3 X n 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,-2) or (0,-1) and new values introduced in order 0..2.

%I A275143 #7 Feb 01 2019 05:03:56
%S A275143 5,36,80,224,528,1216,2816,6544,15216,35376,82240,191184,444448,
%T A275143 1033216,2401936,5583824,12980816,30176736,70152400,163084544,
%U A275143 379125568,881360016,2048913456,4763145904,11072970816,25741534096,59841806560
%N A275143 Number of 3 X n 0..2 arrays with no element equal to any value at offset (-2,-2) (-1,-2) or (0,-1) and new values introduced in order 0..2.
%H A275143 R. H. Hardin, <a href="/A275143/b275143.txt">Table of n, a(n) for n = 1..210</a>
%F A275143 Empirical: a(n) = 3*a(n-1) - 2*a(n-2) + a(n-3) for n>5.
%F A275143 Empirical g.f.: x*(5 + 21*x - 18*x^2 + 51*x^3 - 20*x^4) / (1 - 3*x + 2*x^2 - x^3). - _Colin Barker_, Feb 01 2019
%e A275143 Some solutions for n=5:
%e A275143 ..0..1..2..1..2. .0..1..2..1..0. .0..1..0..1..2. .0..1..2..0..2
%e A275143 ..2..1..2..0..1. .2..1..2..0..1. .2..1..2..0..1. .2..0..2..0..1
%e A275143 ..1..2..1..2..1. .2..0..1..0..1. .2..0..1..2..1. .0..2..1..2..1
%Y A275143 Row 3 of A275142.
%K A275143 nonn
%O A275143 1,1
%A A275143 _R. H. Hardin_, Jul 17 2016