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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 10 |
| 3 | 77 |
| 4 | 538 |
| 5 | 3581 |
| 6 | 23170 |
| 7 | 147197 |
| 8 | 923338 |
| 9 | 5738621 |
| 10 | 35418130 |
| 11 | 217421117 |
| 12 | 1329029338 |
| 13 | 8096512061 |
| 14 | 49190221090 |
| 15 | 298195475837 |
| 16 | 1804438818538 |
| 17 | 10902948379901 |
| 18 | 65799224576050 |
| 19 | 396702889799357 |
| 20 | 2389754663090938 |
| 21 | 14386213437758141 |
| 22 | 86555704435827010 |
| 23 | 520526335200999677 |
[0,1,10,77,538,3581,23170,147197,923338,5738621, 35418130,217421117,1329029338,8096512061, 49190221090,298195475837,1804438818538, 10902948379901,65799224576050,396702889799357, 2389754663090938,14386213437758141, 86555704435827010,520526335200999677] |