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A001180
as a simple table
n
a(n)
1
1
2
1
3
2
4
3
5
3
6
5
7
9
8
16
9
28
10
50
11
89
12
159
13
285
14
510
15
914
16
1639
17
2938
18
5269
19
9451
20
16952
[1,1,2,3,3,5,9,16,28,50,89,159,285,510,914,1639, 2938,5269,9451,16952]