 1-queens: solutions:          1  in          0 msecs
 2-queens: solutions:          0  in          0 msecs
 3-queens: solutions:          0  in          0 msecs
 4-queens: solutions:          2  in          0 msecs
 5-queens: solutions:         10  in          0 msecs
 6-queens: solutions:          4  in          0 msecs
 7-queens: solutions:         40  in          0 msecs
 8-queens: solutions:         92  in          0 msecs
 9-queens: solutions:        352  in         10 msecs
10-queens: solutions:        724  in         60 msecs
11-queens: solutions:       2680  in        280 msecs
12-queens: solutions:      14200  in       1472 msecs
13-queens: solutions:      73712  in       8062 msecs
14-queens: solutions:     365596  in      47358 msecs
15-queens: solutions:    2279184  in     293983 msecs
16-queens: solutions:   14772512  in    1957194 msecs
17-queens: solutions:   95815104  in   13754287 msecs
18-queens: solutions:  666090624  in  101885665 msecs
