BYJ48 Stepper Motor- Step angle!
You need 2048 steps, or 4096 steps, depending on what is meant by a step. 

That motor (I bought some a while ago) uses 2048 full steps, or 4096 half steps per revolution.

A full step sequence is 1A-1B-2A-2B, or the higher torque 1A1B - 2A1B - 2A2B - 1A2B.

A half step sequence is 1A - 1A1B - 1B - 2A1B - 2A - 2A2B - 2B - etc

It's a bit disingenuous for them to quote 4096 half-steps as the motor resolution, as the backlash and stiffness can come to 10s of steps. But with constant load, and stepping in one direction, you can just about see half steps.

I'm not sure where the 4048 in your question came from, it's not in the data sheet. It looks like a random character combination of '4096' and '2048', binary 2^12 and 2^11.