2 0.487115
3 0.880007
4 1.301547
5 2.172839
6 2.662308
7 3.880329
8 4.491871
9 6.922392
10 8.729740
11 10.901971
12 13.885037
13 18.246820
14 21.987255
15 28.236579
16 41.065607
17 44.456013
18 50.782835
19 59.535617
20 83.400427
21 96.250559