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%I #4 Nov 03 2013 10:55:50
%S 0,2,50,136,2820,38000,421920,6118120,80521240,1094128296,15096212664,
%T 206478042568,2844940947752,39196681965960,540088040101912,
%U 7448443982546312,102716411297423656,1416714539550709832
%N Number of 3Xn 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero
%C Row 3 of A231080
%H R. H. Hardin, <a href="/A231082/b231082.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 16*a(n-1) -22*a(n-2) +202*a(n-3) -4786*a(n-4) +10954*a(n-5) -108876*a(n-6) +494726*a(n-7) -867601*a(n-8) +5712046*a(n-9) -8074486*a(n-10) +12131984*a(n-11) -53462460*a(n-12) -197644232*a(n-13) -17742728*a(n-14) -134970336*a(n-15) +1087452416*a(n-16) +2848787264*a(n-17) -3062176448*a(n-18) +24945118592*a(n-19) -26105584256*a(n-20) -10840879872*a(n-21) -37458373632*a(n-22) +16021963776*a(n-23) +13901665280*a(n-24) +34409371648*a(n-25) +2558844928*a(n-26) -74692345856*a(n-27) +18690605056*a(n-28) +56174247936*a(n-29) +5405671424*a(n-30) -17857249280*a(n-31) -23081254912*a(n-32) +14482931712*a(n-33) -486539264*a(n-34) -268435456*a(n-35)
%e Some solutions for n=3
%e ..0..3..2....0..1..2....0..1..2....0..1..2....0..1..0....0..3..0....0..1..0
%e ..2..1..2....0..3..2....2..3..2....0..3..2....2..3..2....0..1..2....0..3..2
%e ..0..3..0....2..1..2....2..1..0....2..1..0....2..1..0....2..3..2....0..1..2
%K nonn
%O 1,2
%A _R. H. Hardin_, Nov 03 2013
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