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A172974
as a simple table
n
a(n)
0
2
1
3
2
4
3
5
4
6
5
7
6
8
7
9
8
10
9
11
10
12
11
14
12
15
13
20
14
21
15
28
16
35
17
36
18
45
19
50
20
55
21
56
22
66
23
70
24
78
25
84
26
91
[2,3,4,5,6,7,8,9,10,11,12,14,15,20,21,28,35,36,45, 50,55,56,66,70,78,84,91]