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A228790 Number of n X n binary arrays with top left element equal to 1 and no two ones adjacent horizontally or nw-se. 1
1, 2, 36, 586, 37944, 3835792, 1104367784, 619684261316, 861640042953968, 2553753667566404176, 17730379458709838261420, 271886420146092794204826516, 9552041362065797908250895398960, 751574042423604397352344101718881740 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Diagonal of A228796

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..29

EXAMPLE

Some solutions for n=4

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

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

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

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

CROSSREFS

Sequence in context: A230132 A141132 A064030 * A124104 A262973 A207832

Adjacent sequences:  A228787 A228788 A228789 * A228791 A228792 A228793

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 04 2013

STATUS

approved

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Last modified July 23 14:56 EDT 2017. Contains 289688 sequences.