Amount
Key Amount in Step Up Rule refers to a 1D-array of r numbers a₁ , a₂ , ... , aᵣ that are interpreted according to the choice made through the key Method
These numbers are used in the generation of the requested sequence of u numbers x₁ , x₂ , ... , xᵤ corresponding to the given externally provided seed number x₀
Look at Method for details of how exactly they are used.
Their number r can be anything, greater or smaller than u, and commonly equals 1.