What is this series of numbers called?

Question

This doesn't seem to be an arithmetic or geometric progression, but is there a name for a series where the interval is increasing or decreasing by a constant, such as:

0, 5, 15, 30, 50, 75, 105...

(increasing interval with a constant of 5)

Answer 1

Take 5 common from the sequence, we get:

5 {0,1,3,6,10,15,21....}

And {0,1,3,6,10,15,21....} is called triangular number sequence.

Or,

0, 5, 15, 30, 50, 75, 105... can be also called monotonically increasing sequence.