A163706 Number of nX4 binary arrays with all 1s connected, a path of 1s from left column to lower right corner, and no 1 having more than two 1s adjacent

1, 11, 63, 259, 896, 2821, 8515, 24940, 70944, 196626, 534162, 1430008, 3786133, 9937397, 25902833, 67151065, 173338487, 445930356, 1144130515, 2929289696, 7487194973

Offset

1,2

Links

Table of n, a(n) for n=1..21.

Example

All solutions for n=2
...0.0.0.0...0.0.0.1...1.0.0.0...1.0.0.1...1.1.0.0...1.1.0.1...1.1.1.0
...1.1.1.1...1.1.1.1...1.1.1.1...1.1.1.1...0.1.1.1...0.1.1.1...0.0.1.1
------
...1.1.1.0...1.1.1.1...1.1.1.1...0.1.1.1
...1.0.1.1...0.0.0.1...1.0.0.1...1.1.0.1

Crossrefs

Sequence in context: A298046 A120723 A053367 * A180763 A362164 A357959

Adjacent sequences: A163703 A163704 A163705 * A163707 A163708 A163709

Keyword

nonn

Author

R. H. Hardin Aug 03 2009

Status

approved