A Notation for Large Numbers defined by Steinhaus (1983, pp. 28-29). In this notation, denotes , denotes `` in Triangles,'' and denotes `` in Squares.'' A modified version due to Moser eliminates the circle notation, continuing instead with Polygons of ever increasing size, so in a Pentagon is with Squares around it, etc.
See also Circle Notation, Large Number, Mega, Moser
References
Steinhaus, H. Mathematical Snapshots, 3rd American ed. New York: Oxford University Press, 1983.