A163884 Number of nXnXn triangular binary arrays with all 1s connected, no 1 having more than 4 1s adjacent, and a path of 1s from peak vertex to anywhere on the bottom side

1, 3, 17, 158, 2798, 95400, 6205642, 775567476, 186046719370

Offset

1,2

Links

Table of n, a(n) for n=1..9.

Example

All solutions for n=3
....1......1......1......1......1......1......1......1......1......1......1..
...1.0....1.1....1.0....1.1....1.0....1.1....1.0....1.1....1.0....1.1....1.1.
..0.1.0..0.1.0..1.1.0..1.1.0..0.1.1..0.1.1..1.1.1..1.1.1..1.0.0..1.0.0..1.0.1
------
....1......1......1......1......1......1..
...0.1....0.1....0.1....0.1....0.1....1.1.
..0.1.0..1.1.0..0.1.1..1.1.1..0.0.1..0.0.1

Crossrefs

Sequence in context: A356639 A354772 A066211 * A221410 A175607 A052143

Adjacent sequences: A163881 A163882 A163883 * A163885 A163886 A163887

Keyword

nonn

Author

R. H. Hardin Aug 06 2009

Status

approved