MathDB

11

Part of 1989 IMO Shortlist

Problems(1)

Show that n|a_n

Source: IMO Shortlist 1989, Problem 11, ILL 35

9/18/2008
Define sequence (an) (a_n) by \sum_{d|n} a_d \equal{} 2^n. Show that n∣an. n|a_n.
modular arithmeticnumber theorySummationNumber theoretic functionsIMO Shortlist