Kekule system

The German mathematician Stephan Kekule of Stradonitz (1863-1933) developed a logical developed numbering system.

The starting-person receives the number 1.
The father of the starting-person receives the number 2 and the mother the number 3.

The number of the father of a person is always twice as largely like those the person and the number of the mother is twice as large plus 1.
The male ancestors have always straight numbers and the female ancestors to have always odd numbers.

A child keeps always the number of the father, or, if this no is blood-related, the number of the mother and additional a letter.
The 1st child a A or a, 2nd child a B or b and so on.
The male children receive capital letters and the female children receive small letters.
The children of these children keep the designation of the father, or, if this no is blood-related, the number of the mother and a further letter attached.

4   5   6   7
|   |   |   |
+ + +   + + +
  |     |  
  2 + 3  
    |    
    1    
 
   1   ?   
   |   |   
   + + +   
    |    
   + + +   
   |   |   
?   1A   1b   ?
|   |   |   |
+ + +   + + +
  |     |  
+ + +   + + +
|   |   |   |
1AB   1Aa   1bA   1bb