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
Sat Oct 1 10:25:43 CEST 2011 [seqfan] Re: more help needed in entering sequences
Wed Jan 26 15:24:23 CET 2011 [seqfan] Experiment: period of a(n) mod p (after ditching rational expressions and linear recurrences)
Fri Oct 29 05:35:16 CEST 2010 [seqfan] Implementing first 500 sequences in Java
Index of A-numbers in seqfan: by ascending order
by month
by frequency
by keyword
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