A212268 - OEIS

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A212268 as a simple table

n	a(n)
1	0
2	0
3	1
4	0
5	2
6	4
7	14
8	48
9	432
10	2316
11	24743
12	223506
13	2537594
14	26771235
15	344781871
16	3927465497
17	53273396228
18	660418431957

[0,0,1,0,2,4,14,48,432,2316,24743,223506,2537594, 26771235,344781871,3927465497,53273396228, 660418431957]