log₁₀(x) = log₂(x) / log₂(10) for all x. 1/log₂(10) is a constant multiplier and can be omitted from asymptotic analysis.
More generally, the base of any logarithm can be changed from a to b (both constant wrt. n) by dividing by logₐ(b), so you can freely switch between log bases greater than one: O(log₁₀(n)) is the same as O(log₂(n)), O(ln(n)), etc.
An example consequence of this is that B-trees don't beat balanced binary search trees asymptotically, even though they give higher log bases in analysis. The just have better constants.
