n | a(n) |
---|---|
1 | 0 |
2 | 20 |
3 | 84 |
4 | 501 |
5 | 2190 |
6 | 9996 |
7 | 42362 |
8 | 178400 |
9 | 732378 |
10 | 2974934 |
11 | 11933578 |
12 | 47466417 |
13 | 187325260 |
14 | 734639334 |
15 | 2865135348 |
16 | 11121381104 |
17 | 42989239524 |
18 | 165564387000 |
19 | 635557701344 |
20 | 2432620417837 |
21 | 9286486715514 |
22 | 35366757558512 |
23 | 134400104565934 |
[0,20,84,501,2190,9996,42362,178400,732378, 2974934,11933578,47466417,187325260,734639334, 2865135348,11121381104,42989239524,165564387000, 635557701344,2432620417837,9286486715514, 35366757558512,134400104565934] |