A218586 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..2 n X n array.

1, 13, 449, 56629, 28543403, 57707873919, 467122877883141, 15124271280844676313, 1958173356335852318774549, 1013875932726564267833657180687

Offset

1,2

Comments

Diagonal of A218592.

Links

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

Example

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

Crossrefs

Cf. A218592.

Sequence in context: A372812 A012832 A102075 * A251601 A338177 A166184

Adjacent sequences: A218583 A218584 A218585 * A218587 A218588 A218589

Keyword

nonn

Author

R. H. Hardin, Nov 03 2012

Status

approved