Genealogy Forum UK

We all have two parents, four grandparents and eight great grandparents
which isn"™t very difficult to understand. But if we take it
back a little farther...it starts to become very complicated. One article
I read recently, said that by the time we go back ten generations
we have 4,096 10th great grandparents. If we go back 20 generations
we have 4,194,304 20th great grandparents; and if we go back
30 generations we will find that we all have 4,294,967,296 30th
great grandparents.

mumbles wrote:We all have two parents, four grandparents and eight great grandparents
which isn"™t very difficult to understand. But if we take it
back a little farther...it starts to become very complicated. One article
I read recently, said that by the time we go back ten generations
we have 4,096 10th great grandparents. If we go back 20 generations
we have 4,194,304 20th great grandparents; and if we go back
30 generations we will find that we all have 4,294,967,296 30th
great grandparents.

Unless there are repeated ancestors in a tree the numbers follow the pattern below --- ^ means "to the power of"

2^1=2 parents
2^2=4 grandparents
2^3=8 Great grandparents
2^4 = 16 Great x2 Grandparents
2^5 = 32 Great x3 Grandparents

2^32 = 4,294,967,296 Great x 30 Grandparents

2^(n+2) Great x n Grandparents

Maths girl

Wow , No wander you are Maths Girl.
I just counted on my fingers