Cauchy- Hadamard's formula in Riemann's estate (Q1312710)

This paper contains three sections. The famous formula for the radius of convergence of a power series discovered by Cauchy in 1821 appears in notes by Riemann which were published by Neuenschwander in 1987. Up to now historians used to believe that the formula had passed unnoticed until 1892. The notes written in 1856 when Riemann prepared his lectures on complex variables, also illustrate Riemann's views on the significance of power series.