**Number of solutions to x^2 == 1 mod n (square roots of unity mod n).**

*1, 1, 2, 2, 2, 2, 2, 4, 2, 2, 2, 4, 2, 2, 4, 4, 2, 2, 2, 4, 4, 2, 2, 8, 2, 2, 2, 4, 2, 4, 2, 4, 4, 2*

*1 seqfan posts*

Index of A-numbers in seqfan: by ascending order by month by frequency by keyword

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