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A223397 4X4 square grid graph coloring a rectangular array: number of nX3 0..15 arrays where 0..15 label nodes of the square grid graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph 1
152, 2360, 39480, 672784, 11561512, 199425400, 3445747472, 59582558136, 1030635314552, 17830297764560, 308491144480488, 5337532888545800, 92351643563233552, 1597906958454938296, 27647738113504778888 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 3 of A223402

LINKS

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

FORMULA

Empirical: a(n) = 18*a(n-1) +69*a(n-2) -1554*a(n-3) +2085*a(n-4) +10353*a(n-5) -18959*a(n-6) -11633*a(n-7) +31508*a(n-8) -5302*a(n-9) -10390*a(n-10) +4408*a(n-11) -440*a(n-12) for n>13

EXAMPLE

Some solutions for n=3

..5..1..2....5..4..5....3..7..6....6.10.14....5..9.10....7..6..5...10..9..8

..6..2..3....6..5..1....7.11.10...10.14.10....6..5..6...11.10..9....9.10..9

..5..1..2....2..1..2...11.10.14....6.10..6....2..1..5....7..6.10...10.11.10

Vertex neighbors:

0 -> 1 4

1 -> 0 2 5

2 -> 1 3 6

3 -> 2 7

4 -> 0 5 8

5 -> 4 1 6 9

6 -> 5 2 7 10

7 -> 6 3 11

8 -> 4 9 12

9 -> 8 5 10 13

10 -> 9 6 11 14

11 -> 10 7 15

12 -> 8 13

13 -> 12 9 14

14 -> 13 10 15

15 -> 14 11

CROSSREFS

Sequence in context: A085775 A208492 A208485 * A239065 A229418 A035823

Adjacent sequences:  A223394 A223395 A223396 * A223398 A223399 A223400

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 19 2013

STATUS

approved

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Last modified December 2 16:17 EST 2021. Contains 349445 sequences. (Running on oeis4.)