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A274897 Number of 5 X n 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-1) or (-2,0) and new values introduced in order 0..2.

%I A274897 #8 Jan 31 2019 09:22:14
%S A274897 12,26,84,275,913,3064,10337,34921,117975,398560,1346637,4550382,
%T A274897 15376372,51958316,175571071,593268299,2004704682,6774075554,
%U A274897 22890197334,77347965186,261365481435,883176688023,2984330940525,10084314105326
%N A274897 Number of 5 X n 0..2 arrays with no element equal to any value at offset (0,-1) (-1,-1) or (-2,0) and new values introduced in order 0..2.
%H A274897 R. H. Hardin, <a href="/A274897/b274897.txt">Table of n, a(n) for n = 1..210</a>
%F A274897 Empirical: a(n) = 8*a(n-1) - 27*a(n-2) + 56*a(n-3) - 75*a(n-4) + 61*a(n-5) - 28*a(n-6) + 7*a(n-7) - a(n-8) for n>9.
%F A274897 Empirical g.f.: x*(12 - 70*x + 200*x^2 - 367*x^3 + 425*x^4 - 301*x^5 + 126*x^6 - 30*x^7 + 4*x^8) / ((1 - x)^3*(1 - 5*x + 9*x^2 - 13*x^3 + 4*x^4 - x^5)). - _Colin Barker_, Jan 31 2019
%e A274897 Some solutions for n=4:
%e A274897 ..0..1..2..1. .0..1..2..0. .0..1..0..1. .0..1..2..1. .0..1..2..0
%e A274897 ..1..2..0..1. .0..1..2..0. .1..2..0..1. .0..2..0..1. .1..2..0..1
%e A274897 ..1..0..1..2. .1..2..0..1. .1..0..1..2. .1..2..1..2. .2..0..1..2
%e A274897 ..2..0..1..2. .2..0..1..2. .2..0..2..0. .1..0..1..0. .0..1..2..0
%e A274897 ..2..1..2..0. .2..1..2..0. .0..1..2..0. .2..0..2..0. .0..1..0..1
%Y A274897 Row 5 of A274895.
%K A274897 nonn
%O A274897 1,1
%A A274897 _R. H. Hardin_, Jul 10 2016