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URL: https://oeis.org/A240629

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A240629
T(n,k)=Number of nXk 0..3 arrays with no element equal to exactly two horizontal and vertical neighbors, with new values 0..3 introduced in row major order.
5
1, 2, 2, 4, 10, 4, 12, 109, 109, 12, 40, 1332, 4369, 1332, 40, 143, 16624, 180480, 180480, 16624, 143, 528, 208015, 7462748, 24648700, 7462748, 208015, 528, 1979, 2604059, 308596193, 3367163455, 3367163455, 308596193, 2604059, 1979, 7466, 32601488
OFFSET
1,2
COMMENTS
Table starts
...1......2.........4...........12..............40.................143
...2.....10.......109.........1332...........16624..............208015
...4....109......4369.......180480.........7462748...........308596193
..12...1332....180480.....24648700......3367163455........459961775083
..40..16624...7462748...3367163455...1519699081714.....685854075788477
.143.208015.308596193.459961775083.685854075788477.1022628784514567961
LINKS
FORMULA
Empirical for column k:
k=1: a(n) = 4*a(n-1) +a(n-2) -6*a(n-3) -3*a(n-4) for n>6
k=2: [order 10] for n>11
k=3: [order 46]
EXAMPLE
Some solutions for n=3 k=4
..0..1..0..2....0..1..1..2....0..1..1..2....0..1..0..2....0..1..0..0
..3..0..3..0....3..0..3..2....1..2..3..0....3..3..2..1....0..2..1..2
..1..2..2..3....3..2..0..1....2..3..2..2....1..1..3..0....2..1..2..1
CROSSREFS
Column 1 is A204678
Sequence in context: A295416 A202802 A059473 * A360313 A162508 A199400
KEYWORD
nonn,tabl
AUTHOR
R. H. Hardin, Apr 09 2014
STATUS
approved