Some cardinals

• A binary tree with n nodes has exactly n+1 null nodes

• If there are n nodes, there exist 2^n-n different trees.
• No. of nodes in a full binary tree is of the form 2^k - 1
  

• Bucket size is 1, when the overlapping and collision occur at same time

Because If there is only one entry possible in the bucket, when the collision occurs,
there is no way to accommodate the colliding value. This results in the overlapping of values.