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A280852
Number of n X n 0..2 arrays with no element equal to more than one of its king-move neighbors and with new values introduced in order 0 sequentially upwards.
0
1, 9, 46, 124, 282, 712, 1738, 4124, 9562, 21752, 48730, 107992, 237082, 516376, 1117210
OFFSET
1,2
COMMENTS
Diagonal of A280859.
EXAMPLE
Some solutions for n=4
..0..1..1..2. .0..1..2..2. .0..1..1..0. .0..1..1..2. .0..1..2..0
..0..2..0..0. .0..1..0..1. .0..2..0..2. .0..2..0..0. .2..1..2..1
..1..2..1..2. .2..2..0..2. .1..2..1..2. .1..2..1..1. .2..0..0..1
..1..0..0..2. .0..1..1..2. .1..0..0..1. .1..0..0..2. .1..1..2..2
CROSSREFS
Cf. A280859.
Sequence in context: A042003 A117052 A356424 * A009294 A061620 A260513
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 09 2017
STATUS
approved