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A005158
as a simple table
n
a(n)
1
1
2
2
3
3
4
10
5
25
6
140
7
588
8
5544
9
39204
10
622908
11
7422987
12
198846076
[1,2,3,10,25,140,588,5544,39204,622908,7422987, 198846076]