Recurrence formulae for lepton and quark generations

Some phenomenological recurrence equations suggested recently for lepton and quark generations are reviewed. They predict the charged lepton of the fourth generation at 28.5 GeV and the up and down quarks of that hypothetic generation at about 250 GeV and 62 GeV, respectively. The top quark, i.e. the up quark of the third generation, is predicted at about 20 GeV. In the appendix a toy model with a statistical interpretation of mass spectral law is described. (author)