%%
% 60-by-60 sparse adjacency matrix of the
% connectivity graph of the soccer ball and the carbon-60 molecule.
A = bucky;

%%
% The number of vertex pairs on a soccer ball connected by a path of length
% k>1 grows with k, as can be seen here for k=3.
subplot(1,2,1)
spy(A)
title('A')

%%
subplot(1,2,2)
spy(A^3)
title('A^3')