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A275499 Number of n X 3 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.

%I A275499 #8 Feb 04 2019 09:22:34
%S A275499 5,54,80,136,232,516,1168,2660,6024,13716,31168,70868,161176,366452,
%T A275499 833360,1894996,4309160,9799012,22282576,50670228,115222840,262014052,
%U A275499 595814224,1354867540,3080938312,7005983220,15931445856,36227745252
%N A275499 Number of n X 3 0..2 arrays with no element equal to any value at offset (-2,-1) (-2,0) or (-1,-1) and new values introduced in order 0..2.
%H A275499 R. H. Hardin, <a href="/A275499/b275499.txt">Table of n, a(n) for n = 1..210</a>
%F A275499 Empirical: a(n) = 2*a(n-1) + 2*a(n-2) - 2*a(n-3) - 4*a(n-4) + 3*a(n-5) + a(n-6) - a(n-7) for n>11.
%F A275499 Empirical g.f.: x*(5 + 44*x - 38*x^2 - 122*x^3 - 72*x^4 + 141*x^5 + 97*x^6 + 11*x^7 - 106*x^8 - 4*x^9 + 36*x^10) / ((1 - x)*(1 - x - 3*x^2 - x^3 + 3*x^4 - x^6)). - _Colin Barker_, Feb 04 2019
%e A275499 Some solutions for n=4:
%e A275499 ..0..1..2. .0..0..0. .0..0..1. .0..0..0. .0..1..0. .0..1..0. .0..0..0
%e A275499 ..1..2..2. .1..2..1. .2..1..1. .0..1..2. .1..1..2. .0..1..2. .1..2..2
%e A275499 ..1..2..0. .2..2..1. .2..1..2. .1..2..2. .1..2..2. .1..2..2. .1..2..1
%e A275499 ..2..0..0. .0..0..0. .1..0..2. .1..2..0. .0..0..0. .2..2..0. .0..0..1
%Y A275499 Column 3 of A275504.
%K A275499 nonn
%O A275499 1,1
%A A275499 _R. H. Hardin_, Jul 30 2016