A233108 - OEIS

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A233108

Number of n X 3 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally or vertically, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order.

6, 313, 24912, 2154065, 189286871, 16683923848, 1471365099497, 129774107522700, 11446271884607256, 1009582054691903383, 89047037607095248482, 7854117302435219663735, 692748031461206544348041

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

OFFSET

1,1

LINKS

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

FORMULA

Empirical: a(n) = 111*a(n-1) - 2128*a(n-2) + 10532*a(n-3) - 17559*a(n-4) + 9045*a(n-5).

Empirical g.f.: x*(6 - 353*x + 2937*x^2 - 8295*x^3 + 7230*x^4) / ((1 - x)*(1 - 18*x + 27*x^2)*(1 - 92*x + 335*x^2)). - Colin Barker, Oct 07 2018

EXAMPLE

Some solutions for n=3:

..0..1..0....0..1..1....0..0..1....0..1..5....0..1..5....0..1..0....0..1..1

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

..0..1..0....1..0..0....4..0..2....0..1..0....0..0..0....2..1..3....5..1..2

CROSSREFS

Column 3 of A233113.

Sequence in context: A123181 A281932 A074656 * A207816 A204462 A135397

Adjacent sequences: A233105 A233106 A233107 * A233109 A233110 A233111

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 04 2013

STATUS

approved