"friendly numbers"/"amicable numbers"
friendly numbers are pair
s of numbers
such that each number is the sum
s of the other number.
s" made the extraordinary discovery that 220 and 284
are friendly numbers.
the divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110, and the sum of
all these is 284.
on the other hand the divisors of 284 are 1, 2, 4, 71, 142, and the sum of these
the pair is said to be symbolic
Martin Gardners book "mathematical magic show
" tells of talisman
in the middle ages
which were inscribed with these numbers on the grounds that
wearing the charms
would promote love
an arab numerologist
documents the practice of carving 220 on one fruit and 284
on another, and then eating the first one and offering the second one to a lover
as a form of mathematical aphrodisiac
taken from "fermats last theorem" by Simon Singh
so now you know what to do if quoting pi to 100 decimals fails to allure the
object of your affections