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A281393
Number of n X n 0..1 arrays with no element equal to more than two of its horizontal, diagonal or antidiagonal neighbors, with the exception of exactly one element, and with new values introduced in order 0 sequentially upwards.
0
0, 0, 131, 1020, 5892, 23216, 84474, 285076, 886900, 2652496, 7689224, 21516104, 58884471
OFFSET
1,3
COMMENTS
Diagonal of A281400.
EXAMPLE
Some solutions for n=4
..0..0..0..1. .0..0..1..1. .0..0..1..0. .0..1..0..0. .0..1..1..0
..1..0..1..1. .1..1..0..0. .0..1..1..1. .1..1..1..0. .1..0..0..1
..1..0..1..0. .0..1..0..1. .0..1..0..0. .0..0..1..0. .0..1..0..1
..0..1..0..0. .0..0..0..1. .0..1..0..1. .0..1..1..0. .0..1..0..0
CROSSREFS
Cf. A281400.
Sequence in context: A142205 A142807 A103834 * A169645 A221154 A144247
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 21 2017
STATUS
approved