Asked by mathslover

For each positive integer n, let H _{n} = 1/1 +1/2 +⋯+ 1/n sum_{n=4}^{∞} 1/n*H_{n}*H_{n-1}=a/b for relatively prime positive integers a and b, find a+b
Answered by Count Iblis
I reduced this problem to a primary school level problem here:

http://www.jiskha.com/display.cgi?id=1370534461
Answered by mathslover
answer=????????
Answered by Count Iblis
Read this:
http://en.wikipedia.org/wiki/Telescoping_series

Then sum both sides of:

1/H_{n} - 1/H_{n-1} =

-1/[n H_{n}H{n-1}]

from n = 4 to infinity, the left hand side is then a telescoping series.
Answered by mathslover
answer===========
Answered by mathslover
i have got the answer
Answered by help me
what is the answer?
How do you do after that step?

Please explain
Answered by rohit
answer is 6/11 or 11+6= 17
Answered by Andrew
Please stop cheating, mathslover. I will delete your account on Brilliant if you continue this behavior.

-Calvin
Answered by Shame
Do you know his account id Calvin? People like these are shame to the Brilliant community.
Answered by Peter Taylor
Mathslover,
Your account has been tracked on Brilliant. On suspicion of posting problems from Brilliant here, 20, 000 lifetime points will be deducted from your account after the next week.

Peter Taylor,
Brilliant Discussions Manager
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