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A232297 Number of 3Xn 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or antidiagonally.

%I A232297 #6 Jul 23 2025 07:16:23
%S A232297 1,73,1313,20563,336079,5546705,91293443,1501960031,24713799985,
%T A232297 406656992827,6691352475451,110103034876825,1811693873275549,
%U A232297 29810574840844381,490519050740934291,8071261298331724901
%N A232297 Number of 3Xn 0..2 arrays with every 0 next to a 1 and every 1 next to a 2 horizontally or antidiagonally.
%C A232297 Row 3 of A232295
%H A232297 R. H. Hardin, <a href="/A232297/b232297.txt">Table of n, a(n) for n = 1..210</a>
%F A232297 Empirical: a(n) = 17*a(n-1) -26*a(n-2) +300*a(n-3) -357*a(n-4) +649*a(n-5) -2086*a(n-6) -7704*a(n-7) +4629*a(n-8) -5443*a(n-9) +93145*a(n-10) +85905*a(n-11) -157839*a(n-12) -729737*a(n-13) -915875*a(n-14) +3209385*a(n-15) +2752272*a(n-16) -5724052*a(n-17) -1434321*a(n-18) +3054997*a(n-19) -1305232*a(n-20) +1344058*a(n-21) +934144*a(n-22) -1112478*a(n-23) +130446*a(n-24) -347652*a(n-25) -83617*a(n-26) +131475*a(n-27) -44419*a(n-28) +74435*a(n-29) -8240*a(n-30) +8400*a(n-31)
%e A232297 Some solutions for n=4
%e A232297 ..1..2..2..2....1..2..0..2....2..2..1..1....0..1..1..2....1..2..2..0
%e A232297 ..1..2..1..0....2..1..2..1....2..0..2..2....2..2..2..2....0..1..1..2
%e A232297 ..1..0..2..1....0..1..2..2....2..1..1..0....1..2..2..1....0..2..2..1
%K A232297 nonn
%O A232297 1,2
%A A232297 _R. H. Hardin_, Nov 22 2013