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A305041
Number of n X n 0..1 arrays with every element unequal to 0, 2, 3, 6 or 7 king-move adjacent elements, with upper left element zero.
0
1, 4, 5, 11, 55, 137, 116, 273937, 2062731, 1797964, 125122422419, 5525083659668
OFFSET
1,2
COMMENTS
Diagonal of A305047.
EXAMPLE
Some solutions for n=5
..0..1..0..0..1. .0..1..1..0..0. .0..1..1..0..1. .0..0..0..0..1
..1..1..0..1..0. .0..1..1..0..0. .0..1..1..0..0. .0..0..0..0..1
..0..0..0..0..0. .0..1..1..0..0. .1..0..1..1..1. .0..0..0..0..1
..0..0..0..1..0. .0..1..1..0..0. .1..1..0..1..1. .1..1..0..1..0
..1..1..1..0..1. .0..1..1..0..0. .0..1..1..0..0. .0..1..0..0..1
CROSSREFS
Cf. A305047.
Sequence in context: A304135 A251240 A361529 * A316731 A253086 A260624
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 24 2018
STATUS
approved