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A217374
as a simple table
n
a(n)
1
0
2
0
3
0
4
0
5
0
6
0
7
0
8
0
9
0
10
4
11
16
12
60
13
194
14
622
15
2128
16
7438
17
25852
18
90266
19
317350
20
1127800
[0,0,0,0,0,0,0,0,0,4,16,60,194,622,2128,7438, 25852,90266,317350,1127800]