https://en.wikipedia.org/wiki/Hilbert_matrix https://en.wikipedia.org/wiki/Hilbert_matrix "The Hilbert matrices are canonical examples of ill-conditioned matri

https://en.wikipedia.org/wiki/Hilbert_matrix https://en.wikipedia.org/wiki/Hilbert_matrix "The Hilbert matrices are canonical examples of ill-conditioned matrices, being notoriously difficult to use in numerical computation."