**Greatest common prime divisor of n and sigma_2(n) = A001157(n), or 1 if the two are relatively prime.**

*1, 1, 1, 1, 1, 2, 1, 1, 1, 5, 1, 3, 1, 2, 5, 1, 1, 1, 1, 2, 1, 2, 1, 2, 1, 2, 1, 7, 1, 5, 1, 1, 1, 2*

*1 seqfan posts*

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

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