D1, D2, D3.

D4, D5, D6.

D7, D8, D9.

duplicates As pointed out by Jack, the question 2665553: Calculating the summation $\sum_{n=1}^{\infty}\frac{H_{n+1}}{n(n+1)}$ was recently reopened. It has a duplicate in 2685921: How to show $\sum_{n=1}^{\infty}\frac{H_{n+1}}{n(n+1)}=2$? Should we close one questionas a duplciate of the other one - in some direction?

I should point out that I am not an impartial party here - the newer one is my own question, it was a repost in an attempt to resolve the delete/undeleted war (and reverting of many edits) on the older one.

It's possible that you might remember those questions form discussions in this room: 2665553, 2685921.

Several comments about the question (and also the repost) were mentioned in the corresponding answer in the reopen request thread.

I have not preference in which direction they are going to be closed (which of them is chosen as the duplicate target).