(+) Ahnentafel and Kekule Numbering Systems

Genealogists often use terms that are not familiar to others. Most of these terms become familiar soon after we get involved in searching for our family trees. We soon speak of pedigree charts, enumerators, Henry numbers, fan charts, and more. However, one term we do not hear often pops up occasionally: Kekule Numbers.

The German mathematician Stephan Kekulé of Stradonitz (1863-1933) was a genealogist as well as the son of famed mathematician and chemist Friedrich August Kekulé. He used a numbering system to show relationships in text format. In German-speaking counties, lists of names created with Stephan Kekulé’s numbers are still referred to by his name: Kekule numbers. However, in English-speaking countries the same numbers in lists would be called “numbers.”

Indeed, ahnentafel numbers and the Kekule numbers for listing ancestors are the same. However, Stephan Kekule also created a similar system for listing descendants, a system I have rarely seen in English publications.