By studying various ways of describing the Narayana triangle, we provide a number of generalizations of this triangle and study some of their properties. In some cases, the diagonal sums of these triangles provide examples of Somos-4 sequences via their Hankel transforms.

In this paper we present an explicit (rank one) function transform which contains several Jacobi-type function transforms and Hankel-type transforms as degenerate cases. The kernel of the transform, which is given explicitly in terms of basic hypergeometric series, thus generalizes the Jacobi function as well as the Bessel function. The kernel is named the Askey-Wilson function, since it provid...

We present two related techniques to measure the two-point correlation function and the power spectrum with edge correction in any spatial dimensions. The underlying algorithm uses fast Fourier transforms for calculating the two-point function with an heuristically weighted edge corrected estimator. Once the correlation function is measured, we estimate the power spectrum via numerical integrat...

A class of matrices is studied that could be considered as Hankel matrices with respect to a system of orthogonal polynomials. It is shown that they have similar properties like classical Hankel matrices. Main attention is paid to the construction of fast and superfast algorithms. The main tool is the fact that these matrices are matrix representation of multiplication operators.

We show that a fast algorithm for the QR factorization of a Toeplitz or Hankel matrix A is weakly stable in the sense that RR is close to AA. Thus, when the algorithm is used to solve the semi-normal equations RRx = A b, we obtain a weakly stable method for the solution of a nonsingular Toeplitz or Hankel linear systemAx = b. The algorithm also applies to the solution of the full-rank Toeplitz ...