S(n): 1/n =< (1+...+1/n)-ln(n)
Base case is trivial
Assume, 1/k =< (1+...+1/k)-ln(k)
Let n=k+1:
LHS=(1+...+1/k+(1/(k+1)))-ln(k+1)
=1/k+ln(k)+1/(k+1)-ln(k+1)
=(1/k+1/(k+1))+ln(k/(k+1))
>=1/(k+1)
Additionally, 1/k, 1/(k+1) and ln(k/(k+1)) <1 for k<1
Thus, LHS=<1
1/n =<...