What are the last two digits of (1+5^(2n+1))/6?
Note that n is assumed to be any positive integer.
Source: The current issue of Crux (Problem 2578).NOTE: This is from the Problem Section of Crux. It is our hope that one of the Macalester Students will solve the problem and send in a solution by the deadline of April 1. We will not post a solution to the email list or on the web site until then.
© Copyright 2000 Stan Wagon. Reproduced with permission.