A Simple Mathematical Way to Track Family Trees: The Ahnentafel

Family trees become incredibly unwieldy as one adds generations, doubling size in height on the chart with each generation. The Ahnentafel, or Ahnen List, is a great alternative, keeping trees in linear form. One simply needs to remember some simple math formulas:

Whoever is the individual whose tree is being charted receives the number 1. Then, to find anyone’s father’s number, double number of child. Mother is doubled plus 1. Thus, their father is 2, their mother is 3. To reverse this and find someone’s child’s number, divide father’s number by 2; or mother minus 1, then divided by 2.

Algebraically:

 F = 2C

 M = 2C + 1

 C = F/2

 C = (M - 1)/2

This is the system I will use when as I publish my Horn Family Tree. To illustrate, in brief, from my tree:

 1 Kenneth Leroy HORN [Also sisters Ellene Horn Reagan & Patricia Horn Brown]

 PARENTS

 2 Leroy Kenneth Earl HORN

 3 Rose Adelaide COREY

 GRANDPARENTS

 4 Frank Eugene Horn

 5 Bessie Cleo Wharton

 6 Earl Councilman Corey

 7 Mary Ellen Mylon

One then adds basic info to each numbered individual: birth and death dates and places. Marriage date and place. Footnotes are added for sources and miscellaneous explanation. The system sounds difficult to some, but is really quite easy to use.

Corey Name Meaning

English: from the Old Norse personal name Kori, which is of uncertain meaning. Northern Irish: variant of Curry.

Source: Dictionary of American Family Names ©2013, Oxford University Press

Horn Name Meaning

English, Scottish, German, and Dutch: from Middle English, Middle High German, Middle Dutch horn ‘horn’, applied in a variety of senses: as a metonymic occupational name for someone who made small articles, such as combs, spoons, and window lights, out of horn; as a metonymic occupational name for someone who played a musical instrument made from the horn of an animal; as a topographic name for someone who lived by a horn-shaped spur of a hill or tongue of land in a bend of a river, or a habitational name from any of the places named with this element (for example, in England, Horne in Surrey on a spur of a hill and Horn in Rutland in a bend of a river); as a nickname, perhaps referring to some feature of a person’s physical appearance, or denoting a cuckolded husband. Norwegian: habitational name from any of several farmsteads so named, from Old Norse horn ‘horn’, ‘spur of land’. Swedish: ornamental or topographic name from horn ‘horn’, ‘spur of land’. Jewish (Ashkenazic): presumably from German Horn ‘horn’, adopted as a surname for reasons that are not clear. It may be purely ornamental, or it may refer to the ram’s horn (Hebrew shofar) blown in the Synagogue during various ceremonies.

Source: Dictionary of American Family Names ©2013, Oxford University Press