A223372 - OEIS

A223372

3X3 square grid graph coloring a rectangular array: number of nX1 0..8 arrays where 0..8 label nodes of the square grid graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph

9, 24, 68, 192, 544, 1536, 4352, 12288, 34816, 98304, 278528, 786432, 2228224, 6291456, 17825792, 50331648, 142606336, 402653184, 1140850688, 3221225472, 9126805504, 25769803776, 73014444032, 206158430208, 584115552256

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Column 1 of A223379

LINKS

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

FORMULA

Empirical: a(n) = 8*a(n-2) for n>3

EXAMPLE

Some solutions for n=3

..7....3....4....5....2....7....6....2....6....3....5....6....7....7....1....1

..4....4....1....4....5....4....7....5....3....6....8....7....4....8....4....2

..7....3....0....3....2....1....4....4....0....7....5....6....3....7....1....1

Vertex neighbors:

0 -> 1 3

1 -> 0 2 4

2 -> 1 5

3 -> 0 4 6

4 -> 3 1 5 7

5 -> 4 2 8

6 -> 3 7

7 -> 6 4 8

8 -> 7 5

CROSSREFS

Sequence in context: A258438 A038626 A195970 * A180334 A223290 A121089

Adjacent sequences: A223369 A223370 A223371 * A223373 A223374 A223375

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 19 2013

STATUS

approved