Prime Pythagorean triangles.
Sur les nombres pseudo-symétriques
Symmetric Semigroups of Integers Generated by 4 Elements.
The Golomb space is topologically rigid
The Golomb space is the set of positive integers endowed with the topology generated by the base consisting of arithmetic progressions with coprime . We prove that the Golomb space is topologically rigid in the sense that its homeomorphism group is trivial. This resolves a problem posed by T. Banakh at Mathoverflow in 2017.
Triangular repunit-there is but 1
In this paper, we demonstrate that 1 is the only integer that is both triangular and a repunit.
Ueber den grössten gemeinsamen Theiler aller Zahlen, welche durch eine ganze Function von n Veränderlichen darstellbar sind.
Untergruppenkriterien für abelsche Gruppen.
Об одном свойстве фигурных чисел