Simulations
Regarding numerical simulations, for systems with some 25 to 250 stars, von Hoerner (1960, 1963), Aarseth (1968) and van Albada (1968) suggested that the final outcome of the evolution of an open cluster is one or more tightly bound binaries (or even a hierarchical triple system). Van Albada pointed out several observational candidates ( Ori, ADS 12696, Oph, 1 Cas, 8 Lac and 67 Oph) as being OCRs and Wielen (1975) indicated another one, the Ursa Major moving group (Collinder 285).
Read more about this topic: Open Cluster Remnant