A210809 - OEIS

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A210809 as a simple table

n	a(n)
1	1
2	4
3	25
4	249
5	4003
6	103776
7	4345693
8	293974075
9	32139729821
10	5678473177751
11	1621605531925261
12	748478713754793757
13	558410639828147749314

[1,4,25,249,4003,103776,4345693,293974075, 32139729821,5678473177751,1621605531925261, 748478713754793757,558410639828147749314]