It is not difficult to show that $$ S_m = \sum_{d=1}^m \frac {2^d}{\sqrt{d}} = \frac {2^{m+1}}{\sqrt{m}} (1+O(\log(m)/m)). $$
But I was wondering if it is possible to do such things using computer? I tried maple's aysmpt function using the following code:
f := m -> sum(2^d/sqrt(d), d = 1 .. m);
asympt(f(x), x);
It does not work. Does there exist programs that can do such jobs?
The correct relative error term is $O(1/m)$. I didn't get this using computer, but numerical computation does hint the correct order.