n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 4 |
3 | 20 |
4 | 98 |
5 | 489 |
6 | 2442 |
7 | 12208 |
8 | 61036 |
9 | 305177 |
10 | 1525880 |
11 | 7629396 |
12 | 38146974 |
13 | 190734865 |
14 | 953674318 |
15 | 4768371584 |
16 | 23841857912 |
17 | 119209289553 |
18 | 596046447756 |
19 | 2980232238772 |
20 | 14901161193850 |
21 | 74505805969241 |
22 | 372529029846194 |
[0,1,4,20,98,489,2442,12208,61036,305177,1525880, 7629396,38146974,190734865,953674318,4768371584, 23841857912,119209289553,596046447756, 2980232238772,14901161193850,74505805969241, 372529029846194] |