MultiplicativeOrder

MultiplicativeOrder(a, n)

gives the multiplicative order a modulo n.

See

• Wikipedia: Multiplicative order

Examples

The A023394 Prime factors of Fermat numbers integer sequence

>> Select(Prime(Range(500)), IntegerQ(Log(2, MultiplicativeOrder(2, # )))&)
{3,5,17,257,641}

Implementation status

• ☑ - partially implemented

Github

• Implementation of MultiplicativeOrder