A218284 Hilltop maps: number of nX4 binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or vertical neighbor in a random 0..4 nX4 array

15, 255, 4091, 65507, 1048307, 16772877, 268366049, 4293856057, 68701687597, 1099226869621, 17587627901103, 281402014235147, 4502431713002299, 72038899172296611, 1152622254984043291, 18441953971381580525

Offset

1,1

Comments

Column 4 of A218288

Links

R. H. Hardin, Table of n, a(n) for n = 1..203

Example

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

Crossrefs

Sequence in context: A123816 A273921 A182607 * A218634 A218238 A015691

Adjacent sequences: A218281 A218282 A218283 * A218285 A218286 A218287

Keyword

nonn

Author

R. H. Hardin Oct 25 2012

Status

approved