olymmath

VMO 1989 Problem 2

    Let a1a_1 = 1, a2a_2 = 1, an+2a_{n+2} = an+1a_{n+1} + ana_n be the Fibonacci sequence. Show that there are infinitely many terms of the sequence such that 1985an21985a_n^2 + 1956an1956a_n + 1960 is divisible by 1989. Does there exist a term such that 1985an21985a_n^2 + 1956an1956a_n + 1960 + 2 is divisible by 1989?

    Community text Kalva (prase.cz mirror). Quoted with source.

    Solutions

    No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.

    Add a solution

    Similar problems

    These problems have the most words in common with this statement.

    Locator vn-vmo/1989/p2 · Tag 2M42MHCXCQ · Edit this page on GitHub · Keys: j next, k previous