MathDB

53

Part of 1984 IMO Longlists

Problems(1)

Find sequence of natural numbers satisfying conditions

Source:

10/12/2010
Find a sequence of natural numbers aia_i such that ai=∑r=1i+4dra_i = \displaystyle\sum_{r=1}^{i+4} d_r, where dr≠dsd_r \neq d_s for r≠sr \neq s and drd_r divides aia_i.
number theory unsolvednumber theory