TOHU  Help Tohu
Tohu wants to enter Moscow State University, and he must pass the math exam. He does not know math, and asks you to help him. The problem is to find the sum of the sequence on condition
Input
First line contains single integer T <= 20000  the number of test cases.
Each of the next T lines contains single integer 1 <= n <= 10^9.
Output
For each n output the value with 11 digits after decimal point.
Example
Input:
2
2
5
Output: 0.70833333333
0.73809523810
hide comments
pandey101299:
20190415 23:19:15
thanks@deependra_18


deependra_18:
20190103 06:37:03
for ans match take 0.50 intialy as a sum 

markaman:
20181207 13:15:47
Pure mathematics :) 

vivek_dwivedi:
20180626 12:30:16
IITJEE math's. Memories ;) 

ankush:
20170529 19:42:44
ac in one go easy 

cake_is_a_lie:
20170403 15:35:27
When math fails you, put your trust in engineering: there is no need for an O(1) formula for Sn; just O(1) formula for An and solid engineering for 0.01s :) 

vineetpratik:
20160622 11:00:30
try to find ak and then apply summation to get formula O(1) 

sneh sajal:
20151218 10:24:54
@ dashingvimeet: output is right!! actually the formula which u are getting is valid for k>=2.we need to take care of k=1 in the summation! 

shikhar:
20150724 12:38:36
i did the maths but could not find the expression 

dashingvimeet:
20150713 16:29:00
By mathematical induction, we found a[sub]1[/sub] and a[sub]2[/sub] as 1 / 6 and 1 / 24 respectively, therefore S[sub]2[/sub] came out to be 0.208333333333. Output shown above is wrong. 
Added by:  Efim 
Date:  20110615 
Time limit:  0.643s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 