Von Zahlen und Figuren
arXiv:math/0201005
Abstract
Talk at the International Conference ``Géométrie au vingtième ciècle: 1930--2000'', Paris, Institut Henri Poincaré, Sept. 2001. The title is a homage to Hans Rademacher and Otto Toeplitz whose book fascinated the author many years ago.
27 pp., amstex file, no figures. This version contains minor corrections and revisions