When strapped in the driver’s seat and the engine is lit, there are three things you can do. You can accelerate. You can stop. And you can steer. While the first two options receive all of the ...

Given a decreasing sequence {aⁿ} of nonnegative terms, we prove that there exist subsequences {nk } of {n} such that ∑k=1∞nk+1−nkank and ∑n=1∞an have the same convergence. In particular, ∑n=1∞an ...