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A230910 T(n,k)=Number of nXk 0..3 arrays x(i,j) with each element horizontally, vertically or antidiagonally next to at least one element with value (x(i,j)+1) mod 4, no adjacent elements equal, and upper left element zero 8
0, 0, 0, 0, 2, 0, 0, 8, 8, 0, 0, 26, 38, 26, 0, 0, 84, 152, 152, 84, 0, 0, 272, 634, 802, 634, 272, 0, 0, 882, 2676, 4308, 4308, 2676, 882, 0, 0, 2862, 11324, 23614, 30304, 23614, 11324, 2862, 0, 0, 9290, 47954, 130178, 219696, 219696, 130178, 47954, 9290, 0, 0 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Table starts

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

.0....2.....8.....26.......84.......272........882........2862..........9290

.0....8....38....152......634......2676......11324.......47954........203122

.0...26...152....802.....4308.....23614.....130178......718750.......3970738

.0...84...634...4308....30304....219696....1603356....11727974......85870504

.0..272..2676..23614...219696...2121666...20713786...202875672....1989694528

.0..882.11324.130178..1603356..20713786..271505344..3573938648...47146678686

.0.2862.47954.718750.11727974.202875672.3573938648.63341237848.1125893859526

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..180

FORMULA

Empirical for column k:

k=2: a(n) = 5*a(n-1) -6*a(n-2) +a(n-3) for n>4

k=3: [order 8] for n>11

k=4: [order 28] for n>31

k=5: [order 89] for n>94

EXAMPLE

Some solutions for n=4 k=4

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

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

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

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

CROSSREFS

Sequence in context: A091933 A058347 A058547 * A215122 A235789 A236925

Adjacent sequences:  A230907 A230908 A230909 * A230911 A230912 A230913

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Nov 01 2013

STATUS

approved

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Last modified July 22 06:30 EDT 2019. Contains 325213 sequences. (Running on oeis4.)