A221439 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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