A122502 - OEIS

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A122502 as a simple table

n	a(n)
1	0
2	1
3	0
4	22
5	54
6	522
7	2376
8	15236
9	82512
10	483332
11	2728296
12	15667920
13	89257896
14	510388840
15	2913416640
16	16643861824
17	95047963488
18	542884234608
19	3100533567552
20	17708509939040
21	101139309767520
22	577645632221792

[0,1,0,22,54,522,2376,15236,82512,483332,2728296, 15667920,89257896,510388840,2913416640, 16643861824,95047963488,542884234608, 3100533567552,17708509939040,101139309767520, 577645632221792]