A229770 Number of n X n 0..2 arrays with rows in lexicographically nondecreasing order and columns in nonincreasing order

3, 22, 322, 12958, 2179956, 1976588468, 10811999412826, 378274896023686216, 88035611475274172311886, 140618374201747733896872001960

Offset

1,1

Comments

Column 2 of A229774

Links

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

Example

Some solutions for n=3
..1..1..1....1..1..0....1..1..1....1..1..0....2..2..1....1..0..0....1..0..0
..1..1..1....2..1..1....2..1..0....2..0..0....2..2..1....1..0..0....1..2..1
..2..2..0....2..1..2....2..1..1....2..1..2....2..2..1....2..1..0....2..1..1

Crossrefs

Sequence in context: A124567 A161967 A192036 * A102223 A189897 A306578

Adjacent sequences: A229767 A229768 A229769 * A229771 A229772 A229773

Keyword

nonn

Author

R. H. Hardin, Sep 29 2013

Status

approved