A020065 - OEIS

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A020065 as a simple table

n	a(n)
0	1
1	0
2	1
3	3
4	14
5	69
6	400
7	2714
8	21115
9	185345
10	1812263
11	19532170
12	230045568
13	2939471157
14	40499380396
15	598490843642
16	9442855533026
17	158430131720783
18	2816535675036146
19	52888281009012092
20	1046012668844905826

[1,0,1,3,14,69,400,2714,21115,185345,1812263, 19532170,230045568,2939471157,40499380396, 598490843642,9442855533026,158430131720783, 2816535675036146,52888281009012092, 1046012668844905826]