Basic Examples (4) 
Find a sequence which converges to the same limit faster than the input sequence:
Given the first few terms of a sequence, find terms of another sequence with accelerated convergence:
Accelerate the convergence of the sequence by specifying the auxiliary sequences:
Give a finite list and specify auxiliary lists:
Options (5) 
Method (3) 
The default Method is "BrezinskiE", which uses a recursive definition:
The Method "Cramer" calculates determinants:
Use "LinearSolve":
Compare the method outputs in a table:
They are all equivalent:
"BrezinskiE" is generally faster than the "LinearSolve" and "Cramer" methods for sequences and lists:
"BrezinskiE" and "LinearSolve" perform similarly on lists, while the "Cramer" Method is slower:
MinWorkingPrecision (2) 
Set "MinWorkingPrecision", which applies SetPrecision on entries that have smaller Precision than the specified value:
In numeric calculations, the "Cramer" Method preserves higher Precision:
Applications (6) 
Calculate the convergence of the Basel series:
Accelerate the convergence with RichardsonExtrapolate and plot a comparison:
Calculate the convergence of the Leibniz formula for :
Accelerate the convergence and plot a comparison:
Calculate the convergence of Stirling's formula:
Numerically verify the convergence using different orders:
Numerically approximate the Zeta[1.2] function:
Use RichardsonExtrapolate with different orders to attempt to accelerate the convergence:
Plot a comparison when the sequence has more terms:
Compute :
Accelerate a (left) Riemann sum approximating :
Approximate the PolyLog[2,z] function from only 3 terms in its Taylor expansion:
Use an auxiliary sequence:
Compare the approximations with the original function in a plot:
Properties and Relations (5) 
RichardsonExtrapolate is linear:
RichardsonExtrapolate reduces the length of a List:
If a sequence a[k] is convergent, then a[k] and its transformed version both converge to the same limit:
RichardsonExtrapolate can accelerate the convergence of logarithmic sequences:
RichardsonExtrapolate can eliminate series coefficients from the asymptotic expansion of a sequence:
Possible Issues (2) 
A failure to find the appropriate auxiliary sequence can cause divergent behavior:
Use an appropriate auxiliary sequence:
Numeric errors can have a dramatic effect on the results:
Neat Examples (2) 
Consider the PrimeZetaP[2] partial sums:
Approximate with RichardsonExtrapolate and compare the results:
Compare the limits in a table:
Approximate the Eigenvalues of an operator by a sequence of truncated matrix representations:
Accelerate the convergence using RichardsonExtrapolate:
Approximating the ground state of the antiferromagnetic Heisenberg spin chain (4) 
Construct the Hamiltonian of the model, which is a 2n×2n dimensional matrix, where n is the length of the spin chain:
Calculate the ground state energy density by exact diagonalization:
Use Richardson Extrapolation to estimate the thermodynamic limit as n→∞:
Compare the results with the exact ground state: