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A217990
as a simple table
n
a(n)
1
1
2
2
3
5
4
10
5
17
6
26
7
37
8
50
9
65
10
82
11
101
12
122
13
145
14
170
15
197
16
226
17
257
18
290
19
420
[1,2,5,10,17,26,37,50,65,82,101,122,145,170,197, 226,257,290,420]