About characteristics of graded algebras $S_{1,4}$ and $SI_{1,4}$

Hilbert series for the graded algebras of comitants $S_{1,4}$ and invariants $SI_{1,4}$ of differential system are constructed and with their help the Krull dimensions of these algebras are determined. The lower bounds for the number of the types of generators for the algebras $S_{1,4}$ and $SI_{1,4}$ are obtained.