There is no clasp to identify a specific point on the chain, and a flipped over necklace is still the same necklace.
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To get you started:
With 1 bead, the necklace can be either 1 black or 1 white bead.
With 2 beads, the necklace can be either 2 black, 2 white, or 1 black-1 white
With 3 beads, the necklace can be either 3 black, 3 white, 2 black-1 white, 2 white-1 black, etc...
# Beads Number of Necklaces 1 2 2 3 3 4 4 6 5 8 6 13