MathDB
Binary Sequences

Source: AIME 2008I Problem 11

March 23, 2008
floor functionAMCAIMEsearchratioalgebrapolynomial

Problem Statement

Consider sequences that consist entirely of A A's and B B's and that have the property that every run of consecutive A A's has even length, and every run of consecutive B B's has odd length. Examples of such sequences are AA AA, B B, and AABAA AABAA, while BBAB BBAB is not such a sequence. How many such sequences have length 14?
Back to ProblemsView on AoPS