OFFSET
2,1
EXAMPLE
One solution for n=9
...1.2.2.2.2.2.2................
.....2.2.2.2.2.2.2..............
.......2.2.2.2.2.2.3............
.........2.2.2.2.3.3.3..........
...........2.2.3.3.3.3.3........
.............3.3.3.3.3.3.4......
...............3.3.3.3.4.4.4....
.................3.3.4.4.4.4.4..
...................3.4.4.4.4.4.4
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 17 2009
STATUS
approved