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A018589
as a simple table
n
a(n)
1
1
2
2
3
4
4
5
5
8
6
10
7
17
8
20
9
34
10
40
11
68
12
85
13
136
14
170
15
340
16
680
[1,2,4,5,8,10,17,20,34,40,68,85,136,170,340,680]