Necklace / bracelet (rotations and reflections) (Circular arrangements of n distinct beads when rotation and reflection)

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Circular arrangements of n distinct beads when rotation and reflection are equivalent: (n−1)!/2 for n≥3

What each symbol means

SymbolWhat it stands for
nDistinct beads

When to use this

n≥3 for /2 after rotation quotient; n=1,2 are small cases checked separately.