We study generalized cluster algebras, introduced by Chekhov and Shapiro. When
the coefficients satisfy the normalization and quasireciprocity conditions, one can
naturally extend the structure theory of seeds in the ordinary cluster algebras by
Fomin and Zelevinsky to generalized cluster algebras. As the main result,
we obtain formulas expressing cluster variables and coefficients in terms of
-vectors,
-vectors, and
-polynomials.