I am X. I was roaming around some place and found another X. We got attracted. Got into some operation and generate Y.
At first Y is 0
Me and my X got together now and went to roam the places.
We are now 2X
We found the group of X with the same number of members as ours and also got into some private operation and got another Y.
We have Y+1
Now, we all X's got together and the same process happened, got Y and again went around with all the X's.
Now tell me What am I?