A021684 - OEIS

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A021684 as a simple table

n	a(n)
0	1
1	23
2	360
3	4810
4	59111
5	690573
6	7801990
7	86089520
8	933531621
9	9989073523
10	105774639620
11	1110701801430
12	11583617458531
13	120125571974873
14	1239860303429250
15	12746044308940540
16	130587414625807841

[1,23,360,4810,59111,690573,7801990,86089520, 933531621,9989073523,105774639620,1110701801430, 11583617458531,120125571974873,1239860303429250, 12746044308940540,130587414625807841]