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A227847
as a simple table
n
a(n)
1
0
2
1
3
1
4
1
5
2
6
2
7
2
8
6
9
10
10
31
11
77
12
206
13
568
14
1704
15
5037
16
15554
[0,1,1,1,2,2,2,6,10,31,77,206,568,1704,5037,15554]