I need help solving the following inequality I encountered in the middle of a proof in my calculus I textbook:
$2^n \leq (n+1)!$
Where $\mathbf{n}$ in an integer.
I've tried applying lg to both members, but got stuck at:
$n \leq \lg(n+1) + \lg(n) + \lg(n-1) + ... + \lg(3) + 1$
A proof by induction is acceptable, but I wanted an algebraic one. I find it more... elegant?
$(n+1)!=2\cdot 3\cdot \dots\cdot(n+1)$ here a product of $n$ numbers all are at least 2 so the result follows...