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Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,2,1,1,1 for x=0,1,2,3,4
1

%I #5 Mar 31 2012 12:36:30

%S 2,8,11,24,61,121,270,614,1296,2973,6574,14527,32621,72032,160402,

%T 357304,792903,1765982,3926185,8727963,19420018,43174998,96024756,

%U 213571465,474912978,1056243677,2348975193,5223841988,11617743070,25836617638

%N Number of nX3 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 2,2,1,1,1 for x=0,1,2,3,4

%C Every 0 is next to 0 2's, every 1 is next to 1 2's, every 2 is next to 2 1's, every 3 is next to 3 1's, every 4 is next to 4 1's

%C Column 3 of A197545

%H R. H. Hardin, <a href="/A197540/b197540.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 2*a(n-1) +a(n-3) -2*a(n-4) +7*a(n-5) -a(n-6) -6*a(n-7) +a(n-8) -16*a(n-9) +16*a(n-10) -7*a(n-11) -27*a(n-12) +45*a(n-13) -25*a(n-15) +19*a(n-16) +8*a(n-17) -24*a(n-18) +16*a(n-19) -8*a(n-20) +2*a(n-21)

%e Some solutions for n=4

%e ..2..1..0....1..0..0....1..1..2....0..0..0....0..0..0....0..0..1....2..1..0

%e ..1..0..0....2..1..0....2..1..1....0..0..0....0..0..0....0..1..2....1..0..0

%e ..0..0..1....2..1..1....2..1..0....0..0..1....1..0..0....0..1..2....1..0..0

%e ..0..1..2....1..1..2....1..0..0....0..1..2....2..1..0....0..0..1....2..1..0

%K nonn

%O 1,1

%A _R. H. Hardin_ Oct 16 2011