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A233213 Number of n X 4 0..5 arrays with no element x(i,j) adjacent to value 5-x(i,j) horizontally or antidiagonally, top left element zero, and 1 appearing before 2 3 and 4, and 2 appearing before 3 in row major order. 1
23, 7222, 3054973, 1340889772, 591021089923, 260625046992322, 114934898294104873, 50686253523654314872, 22352636009353302099823, 9857512392190471938857422, 4347162960647215744965074773 (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) = 491*a(n-1) - 22099*a(n-2) + 21609*a(n-3).

Conjectures from Colin Barker, Oct 10 2018: (Start)

G.f.: x*(23 - 4071*x + 17248*x^2) / ((1 - x)*(1 - 49*x)*(1 - 441*x)).

a(n) = (2205 + 486*49^n + 125*441^n) / 3528.

(End)

EXAMPLE

Some solutions for n=2:

..0..1..2..1....0..1..1..1....0..1..5..1....0..0..1..2....0..1..2..1

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

CROSSREFS

Column 4 of A233217.

Sequence in context: A045735 A233109 A193430 * A090674 A013728 A028693

Adjacent sequences:  A233210 A233211 A233212 * A233214 A233215 A233216

KEYWORD

nonn

AUTHOR

R. H. Hardin, Dec 06 2013

STATUS

approved

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Last modified August 3 22:03 EDT 2021. Contains 346441 sequences. (Running on oeis4.)