Subsequence
= Subsequence
{wiki}
A subsequence of $(a_n)$ has the form $(a_{n_k})$, where $n_1<n_2<\cdots$ is a strictly increasing sequence of indices.
= Subsequence
{wiki}
A subsequence of $(a_n)$ has the form $(a_{n_k})$, where $n_1<n_2<\cdots$ is a strictly increasing sequence of indices.