n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 3 |
4 | 6 |
5 | 10 |
6 | 30 |
7 | 126 |
8 | 448 |
9 | 1296 |
10 | 4140 |
11 | 17380 |
12 | 76296 |
13 | 296088 |
14 | 1126216 |
15 | 4940040 |
16 | 23904000 |
17 | 110455936 |
18 | 489602448 |
19 | 2313783216 |
20 | 11960299360 |
21 | 61878663840 |
22 | 309644323296 |
23 | 1587272962528 |
24 | 8699800221696 |
25 | 48793502304000 |
26 | 268603261201600 |
27 | 1487663739072576 |
[0,0,1,3,6,10,30,126,448,1296,4140,17380,76296, 296088,1126216,4940040,23904000,110455936, 489602448,2313783216,11960299360,61878663840, 309644323296,1587272962528,8699800221696, 48793502304000,268603261201600,1487663739072576] |