A223369 - OEIS

A223369

6X6X6 triangular graph coloring a rectangular array: number of nX7 0..20 arrays where 0..20 label nodes of the fully triangulated graph and every array movement to a horizontal or vertical neighbor moves along an edge of this graph

221760, 250834914, 365447949798, 573055927043172, 928457167048336590, 1524391185435213940170, 2520297393549555690831036, 4179551352031701135658304214, 6944490071035753511344864688838

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

OFFSET

1,1

COMMENTS

Column 7 of A223370

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..71

EXAMPLE

Some solutions for n=3

..0..1..0..1..3..6..3....0..1..0..2..5..2..0....0..1..0..2..5..2..5

..1..0..2..0..1..3..1....1..0..2..4..2..4..1....1..0..2..0..2..0..2

..0..2..0..1..4..7..4....0..2..0..2..5..8..4....0..2..0..1..0..2..4

Vertex neighbors:

0 -> 1 2

1 -> 0 2 3 4

2 -> 0 1 4 5

3 -> 1 4 6 7

4 -> 1 2 3 5 7 8

5 -> 2 4 8 9

6 -> 3 7 10 11

7 -> 3 4 6 8 11 12

8 -> 4 5 7 9 12 13

9 -> 5 8 13 14

10 -> 6 11 15 16

11 -> 6 7 10 12 16 17

12 -> 7 8 11 13 17 18

13 -> 8 9 12 14 18 19

14 -> 9 13 19 20

15 -> 10 16

16 -> 10 11 15 17

17 -> 11 12 16 18

18 -> 12 13 17 19

19 -> 13 14 18 20

20 -> 14 19

CROSSREFS

Sequence in context: A294014 A234489 A321160 * A366824 A254509 A254516

Adjacent sequences: A223366 A223367 A223368 * A223370 A223371 A223372

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 19 2013

STATUS

approved