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A223417 3-level binary fanout graph coloring a rectangular array: number of nX1 0..6 arrays where 0..6 label nodes of a graph with edges 0,1 1,3 1,4 0,2 2,5 2,6 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.

%I A223417 #6 Jul 23 2025 04:07:51
%S A223417 7,12,26,48,104,192,416,768,1664,3072,6656,12288,26624,49152,106496,
%T A223417 196608,425984,786432,1703936,3145728,6815744,12582912,27262976,
%U A223417 50331648,109051904,201326592,436207616,805306368,1744830464,3221225472
%N A223417 3-level binary fanout graph coloring a rectangular array: number of nX1 0..6 arrays where 0..6 label nodes of a graph with edges 0,1 1,3 1,4 0,2 2,5 2,6 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph.
%C A223417 Column 1 of A223423
%H A223417 R. H. Hardin, <a href="/A223417/b223417.txt">Table of n, a(n) for n = 1..210</a>
%F A223417 Empirical: a(n) = 4*a(n-2) for n>3
%e A223417 Some solutions for n=3
%e A223417 ..5....0....5....3....3....0....3....4....0....0....1....2....6....1....2....0
%e A223417 ..2....2....2....1....1....1....1....1....2....1....3....0....2....4....5....1
%e A223417 ..0....6....6....4....3....4....0....3....0....3....1....1....5....1....2....0
%K A223417 nonn
%O A223417 1,1
%A A223417 _R. H. Hardin_ Mar 20 2013