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%I #17 Oct 14 2018 21:54:16
%S 16584,406416,9995040,245837376,6045322368,148657436928,3655605662208,
%T 89894348448768,2210574247446528,54359793423323136,
%U 1336750972483608576,32871779997322199040,808343468249908543488,19877815029157007523840
%N Number of (1+2) X (n+2) 0..2 arrays with no increasing sequence of length 3 horizontally or diagonally downwards.
%H R. H. Hardin, <a href="/A234381/b234381.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 24*a(n-1) - 12*a(n-2) + 624*a(n-3) + 1056*a(n-4) - 8448*a(n-5) - 9216*a(n-6).
%F Empirical g.f.: 24*x*(691 + 350*x + 18336*x^2 + 20208*x^3 - 247936*x^4 - 259584*x^5) / (1 - 24*x + 12*x^2 - 624*x^3 - 1056*x^4 + 8448*x^5 + 9216*x^6). - _Colin Barker_, Oct 14 2018
%e Some solutions for n=1:
%e 2 2 1 2 1 2 0 2 1 1 0 0 0 2 2 1 0 2 0 1 0
%e 1 0 1 2 0 2 0 0 0 0 0 0 1 2 0 0 2 1 0 1 2
%e 0 2 0 0 2 0 0 2 0 1 1 2 1 2 2 0 1 0 0 0 0
%Y Row 1 of A234380.
%K nonn
%O 1,1
%A _R. H. Hardin_, Dec 25 2013
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