MathDB
AIME 1996

Source:

July 14, 2004
AMCAIMEgeometrygeometric transformationrotationalgebrapolynomial

Problem Statement

Two of the squares of a 7×7 7\times 7 checkerboard are painted yellow, and the rest are painted green. Two color schemes are equivalent if one can be obtained from the other by applying a rotation in the plane of the board. How many inequivalent color schemes are possible?