ToeplitzMatrix

ToeplitzMatrix[n]
gives the n×n Toeplitz matrix with first row and first column being successive integers.

ToeplitzMatrix[{c₁, c₂, ..., c_n}]
gives the Toeplitz matrix whose first column consists of elements , , ....

ToeplitzMatrix[{c₁, c₂, ..., c_m}, {r₁, r₂, ..., r_n}]
gives the Toeplitz matrix with elements down the first column, and across the first row.