You start a rumor by telling it to n people and each of them tells it to another n-1 people. If each of these people, in turn, tells the rumor to another n-2 people, and so forth with no person hearing the rumor from more than one source, find a closed-form expression (in terms of n) for the total number of people that have been told the rumor.
(In reply to computer aided solution (spoiler)
Sloane A007526 gives the equation as
a(n) = n(a(n-1)+1)
Posted by Dej Mar
on 2008-04-25 23:33:23