login
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
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
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: A368845 A350791 A128613 * A295216 A230250 A137250
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Nov 03 2013
STATUS
approved