# How can I find the function relating these two progressions?

I have two number progressions that are related and I would like to know the mathematical expressions describing each of them. However, I have no idea how I could find this, and I appreciate all ideas! Below you can see both sets and the difference between them (which is also important to me).

A={0.03,0.04,...,0.10,0.11,...,0.21,0.22,...,0.32,0.33,...,0.43,0.44,0.45,...,0.55,0.56,...}
B={0.01,0.02,...,0.08,0.09,...,0.19,0.19,...,0.29,0.29,...,0.39,0.39,0.39,...,0.49,0.49,...}
dif={0.02,0.02,...,0.02,0.02,...,0.02,0.03,...,0.03,0.04,...,0.04,0.05,0.06,...,0.06,0.07,...}


Although A increases linearly, I can see that B increases linearly just like A though there are certain points in which it doesn't increase (Log-Linear plot below):

I am particularly interested in finding in which points this happens. Do you have any tips for my to get any more insight into these progressions? Thanks so much

• Did you try polynomial fitting? I am sorry as I dont know it may be an obvious advice...... – Harish Mar 9 '15 at 19:29
• Well, yes, I tried interpolating a polynomial for B and found a big big function. Goes up to x^54 :) – Sosi Mar 9 '15 at 19:39
• ...but I was trying to see if something simpler could work – Sosi Mar 9 '15 at 19:59