OFFSET
1,1
EXAMPLE
Some solutions for n=4
..1....1....2....3....3....1....1....2....1....3....1....3....4....1....1....1
..3....5....3....5....5....6....3....7....5....7....4....7....7....2....3....5
..1....7....4....6....3....1....4....4....7....6....3....5....5....4....6....4
..5....2....3....7....7....6....5....3....6....4....2....4....6....7....2....2
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 27 2012
STATUS
approved