A181026 Maximum number of 1s in an nX(n+2) binary matrix with no four 1s adjacent in a line along a row, column or diagonally.

3, 6, 12, 18, 25, 34, 44

Offset

1,1

Links

Table of n, a(n) for n=1..7.

Example

Some solutions for 6X8
..0..1..1..1..0..1..1..1....0..1..1..1..0..1..1..1....0..1..1..1..0..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..0
..1..0..0..0..1..0..1..1....1..0..1..0..1..0..1..1....1..0..1..1..1..0..1..1
..1..1..1..0..1..1..0..1....1..1..0..0..1..1..0..1....1..1..0..0..0..1..0..1
..0..1..1..1..0..1..1..1....0..1..1..1..0..1..1..1....0..1..1..1..0..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..0

Crossrefs

Superdiagonal 2 of A181024.

Sequence in context: A273015 A242297 A024513 * A180005 A116958 A242477

Adjacent sequences: A181023 A181024 A181025 * A181027 A181028 A181029

Keyword

nonn,more

Author

R. H. Hardin, Sep 30 2010

Status

approved