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A007991
as a simple table
n
a(n)
2
1
3
2
4
7
5
18
6
42
7
88
8
176
9
324
10
581
11
984
12
1631
13
2594
14
4055
15
6140
16
9164
[1,2,7,18,42,88,176,324,581,984,1631,2594,4055, 6140,9164]