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A181025
Maximum number of 1s in an nX(n+1) binary matrix with no four 1s adjacent in a line along a row, column or diagonally.
0
2, 6, 9, 15, 22, 31, 39
OFFSET
1,1
EXAMPLE
Some solutions for 6X7
..1..1..1..0..1..1..1....1..1..1..0..1..1..1....1..1..1..0..1..1..1
..1..1..1..0..1..1..1....1..1..1..0..1..1..1....1..1..1..0..1..1..1
..1..1..0..0..0..1..0....1..1..0..0..0..1..1....1..0..1..1..1..0..0
..0..0..1..1..1..0..1....0..0..1..1..1..0..0....0..1..0..0..0..1..1
..1..1..1..0..1..1..1....1..1..1..0..1..1..1....1..1..1..0..1..1..1
..1..1..1..0..1..1..1....1..1..1..0..1..1..1....1..1..1..0..1..1..1
CROSSREFS
Superdiagonal 1 of A181024.
Sequence in context: A084140 A294864 A103139 * A345051 A265202 A355738
KEYWORD
nonn,more
AUTHOR
R. H. Hardin, Sep 30 2010
STATUS
approved