ROW, ROW, ROW
YOUR  TREES

How can seven trees be planted so that there are 6 rows of trees
in a straight line with each row having 3 trees? For example, if
you plant them the following way you get only 4 rows of 3 (two 
horizontal, one vertical, one diagonal).

*	*	*

*	*	*

		*

Passed on by Jennifer_ Vahle <Jennifer_Vahle@ben.edu>


Extra: With 10 trees, make 5 rows of 4 trees each.
Hint: remove one tree from the previous case.

I think the next is 19 trees, 9 rows with 5 in each row.