5 papers
Counting contiguous superregular matrices
Carlo Sanna
This short paper has two goals. First, explaining a simple procedure (which is essentially folklore) that, sometimes, makes it possible to obtain a formula for the number of soluti…
Another factor of integer polynomials with minimal integrals
Alice Bazzanella, Carlo Sanna
Let be a positive integer and let be the set of polynomials with integer coefficients, degree less than , and minimal positive integral over . D. Bazzanella ini…
Explicit inequalities for the nth lucky number
Carlo Sanna
Gardiner, Lazarus, Metropolis, and Ulam introduced a variation of the sieve of Eratosthenes that (instead of producing the sequence of prime numbers) produces the sequence of "luck…
A lower bound for the number of Egyptian fractions
Sandro Bettin, Loïc Grenié, Giuseppe Molteni +1
An Egyptian fraction is a sum of the form where are distinct positive integers. We prove explicit lower bounds for the cardinality of the…
On the number of solutions to a random instance of the permuted kernel problem
Carlo Sanna
The Permuted Kernel Problem (PKP) is a problem in linear algebra that was first introduced by Shamir in 1989. Roughly speaking, given an matrix and an…