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A223688 Petersen graph (8,2) coloring a rectangular array: number of n X 4 0..15 arrays where 0..15 label nodes of a graph with edges 0,1 0,8 8,14 8,10 1,2 1,9 9,15 9,11 2,3 2,10 10,12 3,4 3,11 11,13 4,5 4,12 12,14 5,6 5,13 13,15 6,7 6,14 7,0 7,15 and every array movement to a horizontal or antidiagonal neighbor moves along an edge of this graph. 1
432, 12384, 363600, 10817856, 324280368, 9762152544, 294583794768, 8901308553408, 269168305340592, 8142829402619232, 246392700317804880, 7456528028109531456, 225671563725028735536, 6830216796989608170336 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 4 of A223692.

LINKS

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

FORMULA

Empirical: a(n) = 59*a(n-1) - 1103*a(n-2) + 7621*a(n-3) - 16900*a(n-4).

Empirical g.f.: 144*x*(3 - 91*x + 760*x^2 - 1856*x^3) / (1 - 59*x + 1103*x^2 - 7621*x^3 + 16900*x^4). - Colin Barker, Aug 22 2018

EXAMPLE

Some solutions for n=3:

..6.14..6.14....0..8.10..2....4..5..4..3....6..7.15.13....2.10.12.14

..6.14..6..7...10..2.10..8....4..3.11.13...15..9.11..3...12.14..8..0

..6..7.15..9...10..8.10..2...11..9.15..7...15.13.11..9....8.10..8.14

CROSSREFS

Cf. A223692.

Sequence in context: A223436 A230922 A109123 * A269183 A228105 A232905

Adjacent sequences:  A223685 A223686 A223687 * A223689 A223690 A223691

KEYWORD

nonn

AUTHOR

R. H. Hardin, Mar 25 2013

STATUS

approved

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Last modified July 22 05:47 EDT 2019. Contains 325213 sequences. (Running on oeis4.)