n | a(n) |
---|---|
0 | 1 |
1 | 3 |
2 | 18 |
3 | 111 |
4 | 765 |
5 | 5481 |
6 | 40581 |
7 | 306099 |
8 | 2342034 |
9 | 18108270 |
10 | 141176412 |
11 | 1108011312 |
12 | 8744143401 |
13 | 69325981191 |
14 | 551800999215 |
15 | 4406974587918 |
16 | 35300439813735 |
17 | 283495238613855 |
18 | 2281964065354899 |
19 | 18406084773140820 |
20 | 148734744069134439 |
[1,3,18,111,765,5481,40581,306099,2342034, 18108270,141176412,1108011312,8744143401, 69325981191,551800999215,4406974587918, 35300439813735,283495238613855,2281964065354899, 18406084773140820,148734744069134439] |