HilbertMatrix
HilbertMatrix[n] gives the n×n Hilbert matrix with elements of the form 1/(i+j-1).
HilbertMatrix[{m, n}]gives the m×n Hilbert matrix.
Examples
HilbertMatrix[3]HilbertMatrix[{2, 4}] // MatrixFormPlease visit the official Wolfram Language Reference for more details.