Ahnentafel

An Ahnentafel (or Ahnenreihe) is a list of a person's ancestors in a particular order. It is a construct used in genealogy to display a person's ancestry compactly, without the need for a diagram such as a family tree, which is particularly useful in situations where one may be restricted to using plain text, for example in e-mails or newsgroup articles.

It is effectively a graph traversal of the family tree.

After listing the person as #1, you list their father as #2 and their mother as #3, then their grandparents as #4 to #7, and so on back through the generations. In this scheme, any person's father has double that person's number, and a person's mother has double the person's number plus one. Apart from #1, who can be male or female, all odd-numbered persons are male, and all even-numbered persons are female.

Demonstration

1. self
2. father
3. mother
4. father's father
5. father's mother
6. mother's father
7. mother's mother
8. father's father's father
9. father's father's mother
10. father's mother's father
11. father's mother's mother
12. mother's father's father
13. mother's father's mother
14. mother's mother's father
15. mother's mother's mother

For a real-life example, see the article on Prince Philip, Duke of Edinburgh.