A222973 - OEIS

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A222973 as a simple table

n	a(n)
1	1
2	20
3	1884
4	37680
5	1492176
6	26342820
7	810566001
8	14317221700
9	374392387808
10	6675906932160
11	162189676788683
12	2927729818922000
13	67871228115916800
14	1241683361279242560

[1,20,1884,37680,1492176,26342820,810566001, 14317221700,374392387808,6675906932160, 162189676788683,2927729818922000, 67871228115916800,1241683361279242560]