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A187402 Number of (n+1)X(n+1) 0..2 arrays with diagonal zero and the i,j-th 2X2 subblock sum equal to the j,i-th 2X2 subblock sum 0
9, 141, 4743, 378999, 77470101, 43182942669, 69704886620367, 343603587128867631, 5351921330163734358189, 265547472520415711196418101 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Column 2 of A187408

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

Some solutions for 4X4

..0..0..2..1....0..2..0..0....0..2..0..1....0..2..0..2....0..2..0..2

..2..0..2..0....1..0..0..2....2..0..2..0....2..0..1..1....2..0..2..0

..0..2..0..2....0..1..0..1....2..0..0..0....0..1..0..1....0..2..0..1

..2..1..1..0....1..0..2..0....1..0..2..0....2..1..1..0....2..0..1..0

CROSSREFS

Sequence in context: A137059 A263966 A083084 * A303147 A317354 A050787

Adjacent sequences:  A187399 A187400 A187401 * A187403 A187404 A187405

KEYWORD

nonn

AUTHOR

R. H. Hardin Mar 09 2011

STATUS

approved

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Last modified January 24 07:18 EST 2020. Contains 331189 sequences. (Running on oeis4.)