Between each pair of terms in this sequence is the amount the sequence is decreasing by. The 𝒏th term refers to a term's position in the sequence, for example, the first term has 𝒏 = 1, the second ...

For a power series $f(z) = \sum^\infty_{k = 0} a_kz^k$ let $S_n(f)$ denote the maximum modulus of the zeros of the $n$th partial sum of $f$ and let $r_n(f)$ denote ...