Supplementary Note on J. P. Giraud

A Note on P-sets

A P-set is a set S of positive integers such that no element of S divides the sum of any two (not necessarily being different) larger elements. Erdös and Sárközy [2] conjectured that there exists a constant c > 0 such that for every P-set S we have |{s ∈ S : s ≤ N}| < N1−c for infinitely many integers N . For P-sets S consisting of pairwise coprime integers this conjecture has been proved by T....

A note on p-curvatures

In this note, we give an arithmetic criterion for the Lie-irreducibility of linear differential equations based on p-curvatures.

A Note on Weighted Composition Operators on L^p-Spaces

On the Operads of J . P . May

Author's Note. When this manuscript was submitted in January 1972, the editor asked that it be expanded to study the relation of operads to clubs. The author found this too daunting a task at a busy time and the manuscript was never published. Reading through the manuscript now, more than thirty years later, elicits two strong impressions. First, the treatment is very complete: the only item no...

A Note on Beauville p-Groups

We examine which p-groups of order ≤ p6 are Beauville. We completely classify them for groups of order ≤ p4. We also show that the proportion of 2-generated groups of order p5 which are Beauville tends to 1 as p tends to infinity; this is not true, however, for groups of order p6. For each prime p we determine the smallest non-abelian Beauville p-group.