Since you want the list of all the mangas scanlated in 2011-2013, you can use this. It will give you list of seinen titles which are completed. Well, of course the lists is sorted out by the years they were actually created, but still it's better than nothing.
Also some help finding it, at myanimelist they log the start and end date for mangas and animes in their information on each series. So if you go to the main manga page and do an advanced search you can just search for all the manga that ended in a certain year, say for example, if you put '2011' in the end date option. That way you can also narrow down genres you do/don't want and any other conditions you may desire.