series,Frontier vertices out of 32,Adjacency probes in one level Push,1,31 Push,2,62 Push,4,124 Push,8,248 Push,16,496 Push,24,744 Push,31,961 Pull,1,31 Pull,2,30 Pull,4,28 Pull,8,24 Pull,16,16 Pull,24,8 Pull,31,1