%I #6 Dec 18 2015 18:18:30
%S 15,104,2988,262368,78731136,75601620736,242750087582720,
%T 2529851595786153984,87870306455802168307712,
%U 9952833093128726406499139584,3754882287727806523042164409106432
%N 4-level binary fanout graph coloring a rectangular array: number of n X n 0..14 arrays where 0..14 label nodes of a graph with edges 0,1 1,3 3,5 3,6 1,4 4,7 4,8 0,2 2,9 9,11 9,12 2,10 10,13 10,14 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph
%C Diagonal of A223449
%H R. H. Hardin, <a href="/A223441/b223441.txt">Table of n, a(n) for n = 1..13</a>
%e Some solutions for n=3
%e .13.10..2....0..2..9....3..1..0...13.10.13....7..4..8....2..9..2...12..9.11
%e .10.13.10....2..0..2....1..0..1...10.14.10....4..7..4...10..2..9....9.11..9
%e ..2.10.14...10..2..9....4..1..4....2.10.13....1..4..7...14.10..2...11..9..2
%K nonn
%O 1,1
%A _R. H. Hardin_ Mar 20 2013