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A006247
as a simple table
n
a(n)
1
1
2
1
3
1
4
2
5
3
6
16
7
135
8
3315
9
158830
10
14320182
11
2343203071
12
691470685682
13
366477801792538
[1,1,1,2,3,16,135,3315,158830,14320182,2343203071, 691470685682,366477801792538]