On some topological properties of hypercube, incomplete hypercube and supercube

Hamiltonian properties of hypercube, incomplete hypercube and supercube are examined. It is known that in a nonfaulty hypercube there are at least n! Hamiltonian cycles. The authors extend this result showing that the lower bound is at least 2^n-3n! They show that with at most n-2 faulty links a faulty hypercube has at least 2(n-2)! Hamiltonian cycles. They establish that an incomplete hypercube with odd (even) number of nodes has (n-2)! Hamiltonian paths (cycles). They show that a supercube has at least (n-1)! Hamiltonian cycles and when the number of nodes is 2^n-1+2^n-2, then the number of Hamiltonian cycles is at least as high as 2(n-1)!