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A202729
Number of n X n nonnegative integer arrays with each row and column an ascent sequence (interior element no greater than one plus up-steps preceding it) and the lower right element equal to n-1
0
1, 1, 2, 12, 304, 44976, 51871384, 600608922384, 87357442179208880, 194354337721367202187520
OFFSET
1,3
COMMENTS
Diagonal of A202735
EXAMPLE
Some solutions for n=4
..0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0....0..0..0..0
..0..1..1..1....0..0..1..1....0..0..0..1....0..1..1..1....0..0..1..1
..0..1..0..2....0..1..1..2....0..1..1..2....0..0..1..2....0..1..0..2
..0..1..2..3....0..1..2..3....0..1..2..3....0..1..2..3....0..1..2..3
CROSSREFS
Sequence in context: A000178 A108395 A009669 * A012380 A012377 A012425
KEYWORD
nonn
AUTHOR
R. H. Hardin Dec 23 2011
STATUS
approved