The ancestry report uses 'Ahnentafel' numbering. This means that the numbers for a person's parents will be twice as large as that person's number. For example, if a woman's number is 15, her father will be number 30, and her mother will be 31. Her child will be number 7.
This web site produced 6 Feb 2008 by Personal Ancestral File, a product of
The Church of Jesus Christ of Latter-day Saints.