Long Exact Sequence

\usepackage{tikz-cd}

\begin{tikzcd}
  \cdots \arrow[r] & H_n(A) \arrow[r, "i_*"] & H_n(X) \arrow[r, "j_*"] & H_n(X,A) \arrow[dll, "\partial"] \\
  & H_{n-1}(A) \arrow[r, "i_*"] & H_{n-1}(X) \arrow[r] & \cdots
\end{tikzcd}