Calculation of entanglement in graph states up to five-qubit based on   generalized concurrence
  We propose a new classification for the entanglement in graph states based on generalized con- currence. The numerical results indicate that the eight different three-qubit graph states in three categories, 64 four-qubit graph states in five categories and 1024 five-qubit graph states are in ten classes. We also compare this classification with equivalence classes of these graph states under local complementation (LC) operator, and the obtained result suggests that classification by generalized concurrence is not in contradiction with the LC-rule. 
Ahmad Akhound, Saeed Haddadi, and Mohammad Ali Chaman Motlagh
quant-ph