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

1,1

Comments

Column 1 of A223423

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Formula

Empirical: a(n) = 4*a(n-2) for n>3

Example

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

Crossrefs

Sequence in context: A273307 A093025 A104584 * A224699 A078575 A220036

Adjacent sequences: A223414 A223415 A223416 * A223418 A223419 A223420

Keyword

nonn

Author

R. H. Hardin Mar 20 2013

Status

approved