Context: circuit complexity argument:
How do I show that $$\sum_{i=0}^{n/2- \sqrt{n}} (n \choose i} \geq 2^n/50$$$$\sum_{i=0}^{n/2- \sqrt{n}} {n \choose i} \geq 2^n/50$$ ? (as n goes to infinity)
[This shows up in proving Mod2 is not in ACC(3)].
Standard approach would be to use chernoff bounds; but it provides the wrong direction.
Thanks!