Consider the Vandermonde-like matrix
P:=(Pk(xM,l))l,k=0M,N, where the polynomials
Pk satisfy a three-term recurrence relation and
xM,l[−1,1] are arbitrary nodes. If
Pk are the Chebyshev polynomials
Tk, then
P coincides with
A:=(Tk(xM,l))l=0,k=0M,N. This paper presents a
fast algorithm for the computation of the matrix–vector product
Pa in
O(Nlog2N) arithmetical operations. The algorithm divides into a
fast transform which replaces
Pa with
Aã and a
fast cosine
transform on
arbitrary nodes (NDCT). Since the first part of the algorithm was considered in [Math. Comp. 67 (1998) 1577], we focus on approximative algorithms for the NDCT. Our considerations are completed by numerical tests.