Is there a reason why it shouldn't start with two?
Because that's how the sequence is defined. First number is two, second number is one, all further numbers are produced by summing the previous two.
so it's only difference from the Fibonacci sequence is that it starts with (2,1) instead of (0,1)?(which of course leads to a different sequence)
If you did that now it'd be called plagiarism.
i feel like (0,1) makes more sense