n | a(n) |
---|---|
0 | 1 |
1 | 6 |
2 | 30 |
3 | 138 |
4 | 694 |
5 | 3526 |
6 | 18012 |
7 | 92140 |
8 | 471566 |
9 | 2413794 |
10 | 12356010 |
11 | 63250314 |
12 | 323779348 |
13 | 1657433992 |
14 | 8484446994 |
15 | 43432107538 |
16 | 222330112286 |
17 | 1138113767838 |
18 | 5826034724844 |
19 | 29823627148788 |
20 | 152667942902854 |
[1,6,30,138,694,3526,18012,92140,471566,2413794, 12356010,63250314,323779348,1657433992,8484446994, 43432107538,222330112286,1138113767838, 5826034724844,29823627148788,152667942902854] |