A189876 - OEIS

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A189876 as a simple table

n	a(n)
1	1
2	0
3	0
4	2
5	10
6	0
7	0
8	0
9	0
10	16
11	60
12	40
13	304
14	620
15	2512
16	8734
17	28410
18	94312
19	345824
20	1391072
21	5759566
22	25227796
23	121663032
24	635977968

[1,0,0,2,10,0,0,0,0,16,60,40,304,620,2512,8734, 28410,94312,345824,1391072,5759566,25227796, 121663032,635977968]