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A304920
Number of n X n 0..1 arrays with every element unequal to 0, 1, 2, 5 or 7 king-move adjacent elements, with upper left element zero.
0
1, 4, 15, 87, 1054, 21214, 649029, 33757130, 2831764125, 388624884126, 87386482775870, 32119546783363536, 19300894647086693888
OFFSET
1,2
COMMENTS
Diagonal of A304926.
EXAMPLE
Some solutions for n=5
..0..1..1..1..1. .0..0..0..0..1. .0..0..1..0..0. .0..1..0..0..1
..1..0..1..1..1. .0..0..0..1..0. .0..0..0..0..1. .0..0..0..1..0
..1..1..1..1..0. .0..0..0..0..0. .1..0..0..0..0. .0..0..0..0..0
..1..1..1..1..1. .1..0..0..0..1. .0..0..0..0..1. .0..0..0..1..0
..1..1..1..0..1. .0..0..1..0..0. .0..0..1..0..0. .0..1..0..0..1
CROSSREFS
Cf. A304926.
Sequence in context: A034496 A079155 A306178 * A076900 A346941 A081011
KEYWORD
nonn
AUTHOR
R. H. Hardin, May 21 2018
STATUS
approved