n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 13 |
4 | 68 |
5 | 399 |
6 | 2530 |
7 | 16965 |
8 | 118668 |
9 | 857956 |
10 | 6369883 |
11 | 48336171 |
12 | 373537388 |
13 | 2931682810 |
14 | 23317105140 |
15 | 187606350645 |
16 | 1524813969276 |
17 | 12504654858828 |
18 | 103367824774012 |
19 | 860593023907540 |
20 | 7211115497448720 |
21 | 60776550501588855 |
[1,1,3,13,68,399,2530,16965,118668,857956,6369883, 48336171,373537388,2931682810,23317105140, 187606350645,1524813969276,12504654858828, 103367824774012,860593023907540,7211115497448720, 60776550501588855] |