A221439 Hilltop maps: number of n X n binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..1 n X n array

1, 9, 221, 18393, 6415089, 8569227073, 43045366565233, 827667742380908273, 60943705772313538144913, 17137605013408451421126281145, 18409652574456111249919293718583541

Offset

1,2

Comments

Diagonal of A221446

Links

R. H. Hardin, Table of n, a(n) for n = 1..14

Example

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

Crossrefs

Sequence in context: A079913 A368704 A205578 * A205568 A264848 A033632

Adjacent sequences: A221436 A221437 A221438 * A221440 A221441 A221442

Keyword

nonn

Author

R. H. Hardin Jan 17 2013

Status

approved