3 papers
math.NT2025
On the largest singular vector of the Redheffer matrix
François Clément, Stefan Steinerberger
The Redheffer matrix is defined by setting if or divides and 0 otherwise. One of its many interesting properties is tha…
math.CO2025
Small gaps in the Ulam sequence
François Clément, Stefan Steinerberger
The Ulam sequence, described by Stanislaw Ulam in the 1960s, starts and then iteratively adds the smallest integer that can be uniquely written as the sum of two distinct ear…
math.CA2024
Failure of Orthogonality of Rounded Fourier Bases
François Clément, Stefan Steinerberger
The purpose of this note is to prove estimates for $$ \left| \sum_{k=1}^{n} \mbox{sign} \left( \cos \left( \frac{2πa}{n} k \right) \right) \mbox{sign} \left( \cos \left( \frac{2πb}…