Sosa-numbering Stradonitz :
Jerome Sosa presented in 1676 a method of numbering ancestors ancestor charts for. He takes it in the method published in Cologne 1590 by Michel Eyzinger who had used this numbering system perfectly realized.
This method was repeated in 1898 par Stephan Kekulé von Stradonitz (1863-1933). This genealogist, son of the renowned chemist Friedrich Kekule von Stradonitz, popularized the method in his Ahnentafel-atlas. Pedigrees to 32 Ancestors of the rulers of Europe and their wives (Berlin : J. A. Stargardt, 1898-1904), containing 79 pedigree of European rulers or their spouses.
The system now universally recognized by genealogists as the, not its creator Eytzinger, but its imitators, only used for the descent of a person.

Dialing method :
It assigns the 1 the individual studied (topic, called "the deceased" by some, "Conclusive" by other) then number two to his father and three to his mother. Each man has a double issue of her child (2n) each woman and a number double that of her child, plus (2n + 1).
Each level has ancestry corresponding to a theoretical power 2 which is the degree. At the same time, the smallest number of ancestors of this degree is the same as the theoretical number of degree. So, the degree of great-grandfather, whose size is of theoretical 16 (24), the smallest number of descent is 16, that of paternal grandfather's paternal grandfather of the subject.
Many genealogists contemporaries, improperly, describe the degrees of descent of "generations", and, moreover, "Numérotent" of "generations of ancestors" by starting on, This has the effect of terminating the authorization levels linked to the powers of 2, Yet that is the basis of the work of Sosa then Stradonitz.

General Rules :
the 1 is a man or woman.
other than the odd 1 are women.
peers are male.
the father of n is 2n, his mother is 2n +1.
demand further investigation to involve numeracy:
the degree of descent is obtained by taking the logarithm base 2 Number Chart (more precisely, its integer part).
Once the extent of known ancestry, writing the number in base descent 2, carried out immediately by a computer for example, gives details of parentage.
Example :
Pedigree number 38.
38 is between 32 and 25 = 26 = 64, it is the 5th degree of descent.
Where now 38 base 2 : 38=32 4 2=1*32 0*16 0*8 1*4 1*2 0*1, is the binary number 100110. You rule 1 original and converted the remaining digits by replacing 0 by father 1 by mother.
From the "deceased" the ancestor number 38 obtained by taking his father (0), the father of it (0), the mother of the latter (1), the mother thereof (1), and finally the father (0).