n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 6 |
3 | 27 |
4 | 146 |
5 | 780 |
6 | 4332 |
7 | 24017 |
8 | 135954 |
9 | 767394 |
10 | 4395456 |
11 | 25090131 |
12 | 144840476 |
13 | 833196442 |
14 | 4836766584 |
15 | 27981391815 |
16 | 163112472594 |
17 | 947712321234 |
18 | 5542414273884 |
19 | 32312202610863 |
20 | 189456975899496 |
21 | 1107575676600876 |
[1,1,6,27,146,780,4332,24017,135954,767394, 4395456,25090131,144840476,833196442,4836766584, 27981391815,163112472594,947712321234, 5542414273884,32312202610863,189456975899496, 1107575676600876] |