|
%I #4 Mar 20 2013 05:23:35
%S 7,12,26,48,104,192,416,768,1664,3072,6656,12288,26624,49152,106496,
%T 196608,425984,786432,1703936,3145728,6815744,12582912,27262976,
%U 50331648,109051904,201326592,436207616,805306368,1744830464,3221225472
%N 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 Column 1 of A223423
%H R. H. Hardin, <a href="/A223417/b223417.txt">Table of n, a(n) for n = 1..210</a>
%F Empirical: a(n) = 4*a(n-2) for n>3
%e Some solutions for n=3
%e ..5....0....5....3....3....0....3....4....0....0....1....2....6....1....2....0
%e ..2....2....2....1....1....1....1....1....2....1....3....0....2....4....5....1
%e ..0....6....6....4....3....4....0....3....0....3....1....1....5....1....2....0
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 20 2013
|
