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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 2 |
| 4 | 11 |
| 5 | 32 |
| 6 | 125 |
| 7 | 418 |
| 8 | 1511 |
| 9 | 5248 |
| 10 | 18601 |
| 11 | 65250 |
| 12 | 230099 |
| 13 | 809248 |
| 14 | 2849989 |
| 15 | 10030018 |
| 16 | 35311375 |
| 17 | 124293632 |
| 18 | 437545489 |
| 19 | 1540200002 |
| 20 | 5421774299 |
| 21 | 19085364000 |
| 22 | 67183428301 |
| 23 | 236495292002 |
| 24 | 832498651511 |
| 25 | 2930516834432 |
| 26 | 10315851565625 |
[0,1,2,11,32,125,418,1511,5248,18601,65250,230099, 809248,2849989,10030018,35311375,124293632, 437545489,1540200002,5421774299,19085364000, 67183428301,236495292002,832498651511, 2930516834432,10315851565625] |