**a(n) = smallest number k such that p(n)*k+1 is prime, where p(n) is the n-th prime.**

*1, 2, 2, 4, 2, 4, 6, 10, 2, 2, 10, 4, 2, 4, 6, 2, 12, 6, 4, 8, 4, 4, 2, 2, 4, 6, 6, 6, 10, 2, 4, 2*

*2 seqfan posts*

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

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