2013-2014 Fall OMO #2
Source:
October 30, 2013
Online Math Open
Problem Statement
The figure below consists of several unit squares, of which are white and of which are green. Compute .
[asy]
size(4cm);
int N = 4;
path square;
for (int x=-N; x<=N; ++x) {
for (int y=-N+abs(x); y<=N-abs(x); ++y) {
square = rotate(9)*((x+0.5,y+0.5)--(x+0.5,y-0.5)--(x-0.5,y-0.5)--(x-0.5,y+0.5)--cycle);
if ((x+y) % 2 == 0) { filldraw(square, green, black); }
else { filldraw(square, white, black); }
}
}
[/asy]Proposed by Evan Chen