we investigate the long-term behavior of solutions of the difference equation[ x_{n+1}=x_{n}x_{n-3}-1 ,, n=0 ,, 1 ,, ldots ,, ]noindent where the initial conditions $x_{-3} ,, x_{-2} ,, x_{-1} ,, x_{0}$ are real numbers.  in particular, we look at the periodicity and asymptotic periodicity of solutions, as well as the existence of unbounded solutions.

In the title compound, C(13)H(9)ClN(2)O(5)S, the dihedral angle between the two benzene rings is 83.5 (1)°. In the crystal, mol-ecules are linked via N-H⋯O(S) hydrogen bonds into helical chains running along the b axis.