An Introduction to Counting Orbifolds
  We review three methods of counting abelian orbifolds of the form C^3/Gamma which are toric Calabi-Yau (CY). The methods include the use of 3-tuples to define the action of Gamma on C^3, the counting of triangular toric diagrams and the construction of hexagonal brane tilings. A formula for the partition function that counts these orbifolds is given. Extensions to higher dimensional orbifolds are briefly discussed. 
John Davey, Amihay Hanany and Rak-Kyeong Seong
hep-th