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A305580 Number of nXn 0..1 arrays with every element unequal to 0, 1, 2, 7 or 8 king-move adjacent elements, with upper left element zero. 0
1, 4, 6, 15, 76, 1897, 50618, 1944635, 206386330, 39654762470, 12122540208729, 7706375033488022, 9485494637120246765, 20755111336456755801193 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A305586.

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

Some solutions for n=5

..0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..1

..0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .0..0..0..1..0

..0..0..0..0..0. .0..1..0..0..0. .0..0..0..0..0. .0..0..0..0..0

..0..0..0..0..0. .0..0..0..0..0. .0..0..0..1..0. .0..1..0..0..0

..0..0..0..0..0. .0..0..0..0..0. .0..0..0..0..0. .1..0..0..0..0

CROSSREFS

Cf. A305586.

Sequence in context: A294070 A073603 A064910 * A191311 A086714 A239323

Adjacent sequences:  A305577 A305578 A305579 * A305581 A305582 A305583

KEYWORD

nonn

AUTHOR

R. H. Hardin, Jun 05 2018

STATUS

approved

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Last modified August 13 06:22 EDT 2020. Contains 336442 sequences. (Running on oeis4.)