First I'll say that I enjoyed the earlier puzzles in this series, and thought that you could conclude that they related to a real world concept without too much trouble.
However, I don't think I would have ever figured out this puzzle without hints. I can't imagine concluding that the sequence is the cumulative total of days of the month using the numbers alone.
Anyone else have trouble with this one? I did spend ages on the others thinking they were linear number rules. Maybe these could have had contextual hints or something to steer you in the right direction.