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A302723
Number of n X n 0..1 arrays with every element equal to 1, 2, 4 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.
0
0, 3, 22, 89, 1307, 20842, 532511, 17200486, 683140749, 61552556640
OFFSET
1,2
COMMENTS
Diagonal of A302728.
EXAMPLE
Some solutions for n=5
..0..1..0..0..1. .0..0..1..1..1. .0..1..0..1..1. .0..1..1..1..0
..0..0..1..1..0. .1..1..1..0..1. .1..0..0..0..1. .1..0..0..0..1
..0..0..1..0..1. .1..0..0..0..1. .0..1..1..1..1. .1..1..1..1..1
..1..1..1..0..1. .1..0..1..1..1. .1..1..1..1..0. .1..1..0..1..1
..1..0..0..1..0. .1..1..1..0..0. .0..0..1..0..0. .0..0..1..0..0
CROSSREFS
Cf. A302728.
Sequence in context: A368478 A277228 A302272 * A095663 A254332 A009029
KEYWORD
nonn
AUTHOR
R. H. Hardin, Apr 12 2018
STATUS
approved