MathDB
Number Theory Problem

Source: 1991 National High School Mathematics League, Exam Two, Problem 3

February 26, 2020
number theory

Problem Statement

Let ana_n be the number of such numbers NN: sum of all digits of NN is nn, and each digit can only be 1,3,41,3,4. Prove that a2na_{2n} is a perfect square for all n∈Z+n\in\mathbb{Z}_+.
Back to ProblemsView on AoPS