Show by example that if Ʃan and Ʃbn are two convergent series, then Ʃ (anbn) may be a divergent series.
The Attempt at a Solution
I've been trying long and hard to find an example for this particular case, but I'm unable to find one. I've found examples where Ʃan and Ʃbn are divergent, but Ʃ(anbn) is convergent. Can anyone please give an example? Thanks.