A218813 Hilltop maps: number of 4Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..3 4Xn array

1, 225, 3843, 63499, 1015637, 16247233, 259935681, 4158793313, 66538666069, 1064587366577, 17032902497577, 272518501016117, 4360168964895763, 69760670600929839, 1116138204971281197, 17857690900483942101

Offset

1,2

Comments

Row 4 of A218810

Links

R. H. Hardin, Table of n, a(n) for n = 1..210

Example

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

Crossrefs

Sequence in context: A110204 A180697 A230065 * A330819 A297760 A167035

Adjacent sequences: A218810 A218811 A218812 * A218814 A218815 A218816

Keyword

nonn

Author

R. H. Hardin Nov 06 2012

Status

approved