In 1884 she did obtain a position in Stockholm, thereafter winning honors and prizes, including the Prix Bordin in France. G.H. Hardy at Cambridge sponsored the brilliant young mathematician, whose notebooks of original discoveries are being published and are a source of inspiration to other mathematicians. Sierpinski triangles are created by connecting the the midpoints of the sides of a triangle to form four smaller, interior triangles, and then repeating this process for each of the outside three triangles, ad infinitum. A Hungarian stamp commemorating a mathematical congress shows a design of Sierpinski pyramids, with Michelangelo's hand of God from the Sistine Chapel ceiling thrown in for good measure. A full description of the Polish School of Mathematics appears here .
Stamps commemorating mathematical congresses often use eye-catching figures to draw attention.
The Austrian stamp shows Escher's impossible cube. The German stamp issued for the International Congress of Mathematicians held in Berlin in 1998 shows the constant pi calculated to ever increasing accuracy and spiraling outward.