n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 18 |
4 | 93 |
5 | 416 |
6 | 2073 |
7 | 9720 |
8 | 46859 |
9 | 223726 |
10 | 1069831 |
11 | 5121642 |
12 | 24482721 |
13 | 117159620 |
14 | 560315013 |
15 | 2680448172 |
16 | 12821551727 |
17 | 61331067154 |
18 | 293376558067 |
19 | 1403343084750 |
20 | 6712850697141 |
21 | 32110530228584 |
22 | 153599278134609 |
[1,4,18,93,416,2073,9720,46859,223726,1069831, 5121642,24482721,117159620,560315013,2680448172, 12821551727,61331067154,293376558067, 1403343084750,6712850697141,32110530228584, 153599278134609] |