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A223409 4 X 4 X 4 triangular graph without horizontal edges coloring a rectangular array: number of n X 2 0..9 arrays where 0..9 label nodes of a graph with edges 0,1 0,2 1,3 1,4 2,4 2,5 3,6 3,7 4,7 4,8 5,8 5,9 and every array movement to a horizontal or vertical neighbor moves along an edge of this graph. 1
24, 132, 780, 4664, 28060, 169124, 1020056, 6153860, 37128748, 224020376, 1351668764, 8155585924, 49208586616, 296911448452, 1791484795980, 10809344595640, 65220724455836, 393524597542756, 2374423335359192 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A223415.

LINKS

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

FORMULA

Empirical: a(n) = 9*a(n-1) - 17*a(n-2) - 10*a(n-3) + 26*a(n-4) + 10*a(n-5).

Empirical g.f.: 4*x*(6 - 21*x + 32*x^3 + 10*x^4) / (1 - 9*x + 17*x^2 + 10*x^3 - 26*x^4 - 10*x^5). - Colin Barker, Aug 20 2018

EXAMPLE

Some solutions for n=3:

..5..2....2..0....4..1....3..1....6..3....8..5....8..5....4..2....1..4....2..4

..8..4....0..1....7..4....1..0....3..1....4..8....4..2....8..4....0..2....4..8

..4..7....1..4....4..1....0..1....6..3....1..4....8..4....5..2....2..5....1..4

CROSSREFS

Cf. A223415.

Sequence in context: A293365 A093699 A275405 * A205343 A267631 A305681

Adjacent sequences:  A223406 A223407 A223408 * A223410 A223411 A223412

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 20 2013

STATUS

approved

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Last modified October 27 06:31 EDT 2021. Contains 348271 sequences. (Running on oeis4.)