Given a series of the form
the notation is used to indicate the coefficient (Sedgewick and Flajolet 1996). This corresponds to the Wolfram Language functions Coefficient[A[z], z, k] and SeriesCoefficient[series, k].
Given a series of the form
the notation is used to indicate the coefficient (Sedgewick and Flajolet 1996). This corresponds to the Wolfram Language functions Coefficient[A[z], z, k] and SeriesCoefficient[series, k].
Weisstein, Eric W. "Coefficient Notation." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/CoefficientNotation.html