MathDB
All possible 6-digit numbers are written as a sequence

Source: Indian NMO 2005, Problem 4

August 23, 2005
number theory unsolvednumber theory

Problem Statement

All possible 66-digit numbers, in each of which the digits occur in nonincreasing order (from left to right, e.g. 877550877550) are written as a sequence in increasing order. Find the 20052005-th number in this sequence.