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Half the number of nXnXn triangular binary arrays with every element unequal to at most 4 neighbors
1

%I #5 Mar 31 2012 12:36:20

%S 1,4,32,456,11296,490296,37306768,4974819000,1162617751768,

%T 476177297334976,341799731787300184,429977139597378261384,

%U 947959915554749042500496,3662733300047294688846615504

%N Half the number of nXnXn triangular binary arrays with every element unequal to at most 4 neighbors

%H R. H. Hardin, <a href="/A192500/b192500.txt">Table of n, a(n) for n = 1..15</a>

%e Some solutions for 5X5X5 with a(1,1)=0

%e ......0..........0..........0..........0..........0..........0..........0

%e .....0.1........0.0........0.0........1.0........1.1........0.0........0.0

%e ....0.1.1......0.0.0......1.1.0......0.0.1......0.1.1......0.0.1......0.0.1

%e ...0.0.1.0....1.1.1.1....1.1.0.1....1.0.0.1....1.1.1.1....0.0.0.1....1.0.0.0

%e ..0.0.1.0.1..0.0.0.1.1..0.1.0.0.0..0.1.1.1.0..0.1.0.0.0..0.1.0.1.0..0.0.1.1.1

%K nonn

%O 1,2

%A _R. H. Hardin_ Jul 02 2011