# The family tree conundrum ...
# you have two parents, your parents each have two parents, that makes it
# four grandparents for you, then there must be eight great grandparents
# and so on.  A light hearted look at a serious problem.
# tested with Python24    vegaseat      24jul2005
 
generations = 3
number_of_parents = 2 ** generations
print "after 3 generation we have %d great grandparents" % number_of_parents
 
print
 
# going back 40 generations
for generations in range(4, 41):
    number_of_parents = 2 ** generations
    print "In %d generation we have %d (g)parents" % (generations, number_of_parents)
 
print
 
print """Going back in your family tree for 40 generations, or around a thousand years,
there should be over one trillion great-great-great-...-grandparents you could 
lay claim to being related with.
 
Hmmm, that alone is more people then ever lived!  We demand an explanation from 
our government!"""