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A006611
as a simple table
n
a(n)
1
0
2
0
3
0
4
0
5
0
6
2
7
4
8
14
9
38
10
89
11
234
12
581
13
1471
14
3560
15
8940
16
21229
17
52876
18
126393
19
309993
[0,0,0,0,0,2,4,14,38,89,234,581,1471,3560,8940, 21229,52876,126393,309993]