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A163684 Number of n X n binary arrays with all 1s connected, a path of 1s from upper left corner to lower right corner, and no 1 having more than two 1s adjacent 0
1, 3, 17, 132, 1561, 27874, 809249 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..7.

EXAMPLE

All solutions for n=3

...1.0.0...1.0.0...1.0.0...1.0.0...1.1.0...1.1.0...1.1.1...1.1.1...1.1.0

...1.1.0...1.1.1...1.0.0...1.0.1...1.0.0...1.0.1...1.0.0...1.0.1...0.1.0

...0.1.1...0.0.1...1.1.1...1.1.1...1.1.1...1.1.1...1.1.1...1.1.1...0.1.1

------

...1.1.0...1.1.1...1.1.1...1.1.1...1.1.1...1.1.1...1.0.1...1.1.1

...0.1.1...0.0.1...0.0.1...1.0.1...1.0.1...1.0.1...1.0.1...0.0.1

...0.0.1...0.0.1...0.1.1...0.0.1...0.1.1...1.0.1...1.1.1...1.1.1

CROSSREFS

Sequence in context: A073513 A074524 A212280 * A093986 A192459 A055214

Adjacent sequences:  A163681 A163682 A163683 * A163685 A163686 A163687

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 03 2009

STATUS

approved

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Last modified November 18 10:33 EST 2017. Contains 294887 sequences.