The square of a graph is defined as its second graph power
(Harary and Palmer 1973, p. 264).
The square of any biconnected graph is Hamiltonian (Fleischner 1974, Skiena 1990, p. 231). Mukhopadhyay (1967) has considered "square
root graphs," whose square gives a given graph (Skiena 1990, p. 253).
Fleischner, H. "The Square of Every Two-Connected Graph Is Hamiltonian." J. Combin. Th. Ser. B16, 29-34, 1974.Harary,
F. and Palmer, E. M. "A Survey of Graphical Enumeration Problems."
In A Survey of Combinatorial Theory (Ed. J. N. Srivastava). Amsterdam,
Netherlands: North-Holland, pp. 259-275, 1973.Mukhopadhyay, A.
"The Square Root of a Graph." J. Combin. Th.2, 290-295,
1967.Skiena, S. Implementing
Discrete Mathematics: Combinatorics and Graph Theory with Mathematica. Reading,
MA: Addison-Wesley, 1990.