A223832 Number of n X n 0..1 arrays with rows and antidiagonals unimodal and columns nondecreasing.

1, 2, 9, 48, 249, 1240, 5992, 28369, 132427, 611901, 2805670, 12786249, 57979474, 261797013, 1177774158, 5281497918

Offset

0,2

Links

Table of n, a(n) for n=0..15.

Example

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

Crossrefs

Main diagonal of A223838.

Sequence in context: A289576 A370200 A369315 * A323958 A306356 A188818

Adjacent sequences: A223829 A223830 A223831 * A223833 A223834 A223835

Keyword

nonn,more

Author

R. H. Hardin, Mar 27 2013

Extensions

a(0)=1 prepended by Alois P. Heinz, Feb 14 2024

Status

approved