**a(n) = n*a(n-1) + (n-1)*a(n-2), a(0) = 1, a(1) = 1.**

*1, 1, 3, 11, 53, 309, 2119, 16687, 148329, 1468457, 16019531, 190899411*

*3 seqfan posts*

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

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