MathDB
ASU 273 All Soviet Union MO 1979 x_1+x_4/2+x_9/3+...+x_n^2/n \le 1

Source:

July 14, 2019
Sequencealgebrainequalities

Problem Statement

For every nn, the decreasing sequence {xk}\{x_k\} satisfies a condition x1+x4/2+x9/3+...+xn2/n1x_1+x_4/2+x_9/3+...+x_n^2/n \le 1 Prove that for every nn, it also satisfies x1+x2/2+x3/3+...+xn/n3x_1+x_2/2+x_3/3+...+x_n/n\le 3