  The distinguishable cluster approximation applied to coupled cluster doubles
equations greatly improves absolute and relative energies. We apply the same
approximation to the triples equations and demonstrate that it can also improve
results of the coupled cluster with singles, doubles and triples. The resulting
method has a nominal computational scaling of ${\cal O}(N^7)$ in the real-space
representation, is orbital invariant, size extensive, and exact for three
electrons.
