A212931 Number of 2Xn 0..n-1 arrays with no column j greater than column j-1 in all rows

1, 15, 568, 39695, 4431876, 724082352, 163050236504, 48442719007503, 18368207542264060, 8659014569831436140, 4968837728849467193040, 3410836618457710864892912, 2760233360074280192888992948

Offset

1,2

Comments

Row 2 of A212930

Links

R. H. Hardin, Table of n, a(n) for n = 1..17

Example

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

Crossrefs

Sequence in context: A110840 A012178 A012229 * A027462 A329122 A027534

Adjacent sequences: A212928 A212929 A212930 * A212932 A212933 A212934

Keyword

nonn

Author

R. H. Hardin May 31 2012

Status

approved