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%I #8 Jun 07 2018 08:28:44
%S 13693,11671,6786,6772,7376,9272,12896,24064,54880,136096,360416,
%T 973952,2644160,7212160,19693504,53781184,146920256,401383616,
%U 1096566464,2995860928,8184835264,22361328832,61092268736,166907175104,455998779584
%N Number of (n+2) X 9 0..2 arrays with every 3 X 3 subblock having three equal elements in a row horizontally, vertically or nw-to-se diagonally exactly three ways, and new values 0..2 introduced in row major order.
%C Column 7 of A204370.
%H R. H. Hardin, <a href="/A204369/b204369.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 3*a(n-1) -6*a(n-4) +4*a(n-6) for n>9.
%F Empirical g.f.: x*(13693 - 29408*x - 28227*x^2 - 13586*x^3 + 69218*x^4 + 57170*x^5 - 28976*x^6 - 20676*x^7 - 200*x^8) / ((1 - x)*(1 - 2*x - 2*x^2)*(1 - 2*x^3)). - _Colin Barker_, Jun 07 2018
%e Some solutions for n=5:
%e ..0..1..0..0..1..2..0..1..1....0..1..2..0..1..0..2..1..0
%e ..0..1..0..0..1..2..0..1..1....0..1..2..0..1..0..2..1..0
%e ..0..1..0..0..1..2..0..1..1....0..1..2..0..1..0..2..1..0
%e ..0..1..0..0..1..2..0..1..1....0..1..2..0..1..0..2..1..0
%e ..0..1..0..0..1..2..0..1..1....0..1..2..0..1..0..2..1..0
%e ..0..1..0..0..1..2..0..1..1....0..1..2..0..1..0..2..1..0
%e ..0..1..0..0..1..2..0..1..1....0..1..2..0..1..0..2..1..0
%Y Cf. A204370.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 14 2012
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