n | a(n) |
---|---|
0 | 1 |
1 | 21 |
2 | 221 |
3 | 1561 |
4 | 8361 |
5 | 36365 |
6 | 134245 |
7 | 433905 |
8 | 1256465 |
9 | 3317445 |
10 | 8097453 |
11 | 18474633 |
12 | 39753273 |
13 | 81270333 |
14 | 158819253 |
15 | 298199265 |
16 | 540279585 |
17 | 948062325 |
18 | 1616336765 |
19 | 2684641785 |
20 | 4354393801 |
21 | 6911195501 |
22 | 10753517061 |
23 | 16429137361 |
24 | 24680949041 |
25 | 36503969061 |
[1,21,221,1561,8361,36365,134245,433905,1256465, 3317445,8097453,18474633,39753273,81270333, 158819253,298199265,540279585,948062325, 1616336765,2684641785,4354393801,6911195501, 10753517061,16429137361,24680949041,36503969061] |