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.
7, 12, 26, 48, 104, 192, 416, 768, 1664, 3072, 6656, 12288, 26624, 49152, 106496, 196608, 425984, 786432, 1703936, 3145728, 6815744, 12582912, 27262976, 50331648, 109051904, 201326592, 436207616, 805306368, 1744830464, 3221225472
Offset: 1
Keywords
Examples
Some solutions for n=3 ..5....0....5....3....3....0....3....4....0....0....1....2....6....1....2....0 ..2....2....2....1....1....1....1....1....2....1....3....0....2....4....5....1 ..0....6....6....4....3....4....0....3....0....3....1....1....5....1....2....0
Links
- R. H. Hardin, Table of n, a(n) for n = 1..210
Formula
Empirical: a(n) = 4*a(n-2) for n>3
Comments