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A280676
Number of 4Xn 0..2 arrays with no element equal to more than one of its horizontal and antidiagonal neighbors and with new values introduced in order 0 sequentially upwards.
1
14, 612, 12484, 310365, 7533245, 183331502, 4460317695, 108520231044, 2640298250694, 64238619127022, 1562929767205929, 38026186043293995, 925179685380850290, 22509684536321285656, 547662154172647585113
OFFSET
1,1
COMMENTS
Row 4 of A280673.
FORMULA
Empirical recurrence of order 73 (see link above)
EXAMPLE
Some solutions for n=3
..0..1..0. .0..0..1. .0..1..0. .0..0..1. .0..1..2. .0..1..2. .0..1..2
..0..2..0. .1..2..1. .0..1..0. .1..0..1. .0..1..0. .0..2..1. .2..1..2
..1..0..2. .2..1..2. .2..1..2. .2..1..0. .2..1..2. .1..2..0. .2..0..0
..1..2..0. .0..0..2. .1..0..1. .0..2..0. .0..0..2. .0..1..2. .1..2..2
CROSSREFS
Cf. A280673.
Sequence in context: A279294 A282053 A209678 * A209103 A283780 A210808
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 07 2017
STATUS
approved