Mass spectra of neat (NO)(n)(+) clusters and mixed (N2O)(m)(NO)(n)(+) and (NO2)(m)(NO)(n)(+) clusters are obtained and investigated by nonresonant multiphoton ionization with a femtosecond laser. Intensity alternations observed in the mass spectra of neat NO clusters are explainable in terms of the pairing of the number of total valence electrons in the cluster. A series of (N2O)(NO)(n)(+) (n greater than or equal to 3), which is also observed when pure NO sample gas is used, is suggested to be the product of intracluster reactions of pure NO clusters occurring after ionization. For the series of (NO)(n)N2O+ clusters a polymerized core ion structure is proposed to account for its intensity distribution and the observed metastable decay pathways.