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A231063 T(n,k)=Number of nXk 0..3 arrays x(i,j) with each element horizontally or vertically next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero 7
0, 0, 0, 0, 2, 0, 0, 6, 6, 0, 0, 20, 34, 20, 0, 0, 68, 208, 208, 68, 0, 0, 230, 1272, 2376, 1272, 230, 0, 0, 778, 7818, 27346, 27346, 7818, 778, 0, 0, 2632, 47998, 313944, 585880, 313944, 47998, 2632, 0, 0, 8904, 294832, 3607664, 12582344, 12582344, 3607664 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

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

.0....2......6.......20.........68..........230.............778

.0....6.....34......208.......1272.........7818...........47998

.0...20....208.....2376......27346.......313944.........3607664

.0...68...1272....27346.....585880.....12582344.......270096962

.0..230...7818...313944...12582344....505135612.....20286249268

.0..778..47998..3607664..270096962..20286249268...1524513500124

.0.2632.294832.41448458.5799242344.814871303100.114623595936566

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..127

FORMULA

Empirical for column k:

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

k=3: [order 10]

k=4: [order 31]

EXAMPLE

Some solutions for n=4 k=4

..0..1..2..3....0..1..2..3....0..1..0..1....0..3..0..1....0..3..2..3

..1..0..1..0....3..2..3..0....3..2..3..2....1..2..3..2....1..2..1..0

..2..3..0..3....2..3..2..1....1..0..1..0....3..0..2..1....2..3..0..3

..1..2..1..0....1..0..3..2....2..3..2..1....2..1..0..3....1..0..3..2

CROSSREFS

Sequence in context: A257549 A112964 A128613 * A295216 A230250 A137250

Adjacent sequences:  A231060 A231061 A231062 * A231064 A231065 A231066

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Nov 03 2013

STATUS

approved

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Last modified July 14 16:21 EDT 2020. Contains 335729 sequences. (Running on oeis4.)