MathDB
Usamo 1998

Source:

January 14, 2005
AMCUSA(J)MOUSAMOfunctionfloor functionconicshyperbola

Problem Statement

Let n5n \geq 5 be an integer. Find the largest integer kk (as a function of nn) such that there exists a convex nn-gon A1A2AnA_{1}A_{2}\dots A_{n} for which exactly kk of the quadrilaterals AiAi+1Ai+2Ai+3A_{i}A_{i+1}A_{i+2}A_{i+3} have an inscribed circle. (Here An+j=AjA_{n+j} = A_{j}.)