The analytical forms of non-Boltzmann vibrational distributions are studied by means of the vibrational partition function which, being the cumulative quantity, allows to detect general differences in behavior of vibrational distributions. Various forms of the Treanor distributions are studied in both discrete (sum of quantum vibrational levels) and continuous manners (classical values from integration over the phase space). The advantages of the continuous forms of distributions are pointed out (in both classical and quantum vibrational temperature regimes). The typical distribution is not properly described by the Treanor forms so the values based on continuous form of the piecewise Treanor-Hyperbolic distribution are given. The influence of vibrational excitation on rotational partition function is quantified.