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A181027
Maximum number of 1s in an nX(n+3) binary matrix with no four 1s adjacent in a line along a row, column or diagonally.
0
3, 8, 15, 20, 28, 38, 50
OFFSET
1,1
EXAMPLE
Some solutions for 6X9
..0..1..1..1..0..1..1..1..0....1..0..1..1..1..0..1..1..1
..1..1..1..0..1..0..1..1..1....1..1..1..0..1..1..1..0..1
..1..0..1..1..0..1..1..0..1....0..0..0..1..1..1..0..1..0
..1..1..0..1..0..1..0..1..1....1..1..1..0..0..1..0..1..1
..0..1..1..1..0..1..1..1..0....1..0..1..1..1..0..1..1..1
..1..1..1..0..1..0..1..1..1....1..1..1..0..1..1..1..0..1
CROSSREFS
Superdiagonal 3 of A181024.
Sequence in context: A213158 A228880 A310314 * A060320 A162372 A101711
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, Sep 30 2010
STATUS
approved