n | a(n) |
---|---|
0 | 1 |
1 | 6 |
2 | 30 |
3 | 150 |
4 | 750 |
5 | 3750 |
6 | 18735 |
7 | 93600 |
8 | 467640 |
9 | 2336400 |
10 | 11673000 |
11 | 58320000 |
12 | 291375210 |
13 | 1455753000 |
14 | 7273154040 |
15 | 36337737000 |
16 | 181548627000 |
17 | 907043385000 |
18 | 4531720872060 |
19 | 22641137570400 |
20 | 113118421225440 |
21 | 565156109349600 |
[1,6,30,150,750,3750,18735,93600,467640,2336400, 11673000,58320000,291375210,1455753000,7273154040, 36337737000,181548627000,907043385000, 4531720872060,22641137570400,113118421225440, 565156109349600] |