A056418 - OEIS

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A056418 as a simple table

n	a(n)
1	0
2	0
3	0
4	0
5	6
6	150
7	400
8	4080
9	15480
10	127818
11	269340
12	3493680
13	5777190
14	57262450
15	210945182
16	1030388115
17	2493913170
18	32176448060
19	51785999300
20	562228325904
21	1805427491920
22	10438821843750
23	22865672706000

[0,0,0,0,6,150,400,4080,15480,127818,269340, 3493680,5777190,57262450,210945182,1030388115, 2493913170,32176448060,51785999300,562228325904, 1805427491920,10438821843750,22865672706000]