A231063 - OEIS

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

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

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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: A368845 A350791 A128613 * A295216 A230250 A137250

Adjacent sequences: A231060 A231061 A231062 * A231064 A231065 A231066

KEYWORD

nonn,tabl

AUTHOR

R. H. Hardin, Nov 03 2013

STATUS

approved