n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 21 |
3 | 123 |
4 | 757 |
5 | 4788 |
6 | 30817 |
7 | 200784 |
8 | 1320093 |
9 | 8740284 |
10 | 58193673 |
11 | 389233287 |
12 | 2613338091 |
13 | 17602627006 |
14 | 118892784555 |
15 | 804951501469 |
16 | 5461228061541 |
17 | 37120212399708 |
18 | 252720891884473 |
19 | 1723088114793535 |
20 | 11763751150648785 |
[1,4,21,123,757,4788,30817,200784,1320093,8740284, 58193673,389233287,2613338091,17602627006, 118892784555,804951501469,5461228061541, 37120212399708,252720891884473,1723088114793535, 11763751150648785] |