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A230819 T(n,k)=Number of nXk 0..2 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 3 and at least one element with value (x(i,j)-1) mod 3, and upper left element zero 7
0, 0, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 4, 0, 0, 0, 2, 12, 12, 2, 0, 0, 12, 100, 174, 100, 12, 0, 0, 18, 326, 816, 816, 326, 18, 0, 0, 56, 2114, 12210, 28772, 12210, 2114, 56, 0, 0, 170, 9226, 108006, 497166, 497166, 108006, 9226, 170, 0, 0, 420, 47220, 1202184, 10872238 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,8

COMMENTS

Table starts

.0..0....0.......0.........0...........0.............0.............0

.0..0....2.......0.........2..........12............18............56

.0..2....4......12.......100.........326..........2114..........9226

.0..0...12.....174.......816.......12210........108006.......1202184

.0..2..100.....816.....28772......497166......10872238.....222626294

.0.12..326...12210....497166....21835516.....888633610...37511690680

.0.18.2114..108006..10872238...888633610...75341251814.6484756891722

.0.56.9226.1202184.222626294.37511690680.6484756891722

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..112

FORMULA

Empirical for column k:

k=2: a(n) = 2*a(n-1) +a(n-2) +4*a(n-3) -4*a(n-4)

k=3: [order 19]

k=4: [order 95] for n>96

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

CROSSREFS

Sequence in context: A337113 A285244 A263148 * A317573 A032337 A058190

Adjacent sequences:  A230816 A230817 A230818 * A230820 A230821 A230822

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Oct 30 2013

STATUS

approved

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Last modified May 28 15:04 EDT 2022. Contains 354115 sequences. (Running on oeis4.)