in	out
1	1
2	1.4142
3	1.7321
4	2
5	2.2361
6	2.4495
7	2.6458
8	2.8284
9	3
10	3.1623
11      3.3166
12	3.4641
13	3.6056
14	3.7417
15	3.8730
16	4 