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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 7 |
| 3 | 44 |
| 4 | 299 |
| 5 | 1940 |
| 6 | 13549 |
| 7 | 99987 |
| 8 | 768752 |
| 9 | 6089791 |
| 10 | 49392723 |
| 11 | 408550278 |
| 12 | 3435528229 |
| 13 | 29289695650 |
| 14 | 252672394234 |
| 15 | 2201981901415 |
| 16 | 19360330918473 |
| 17 | 171550299264139 |
| 18 | 1530609037414453 |
[0,7,44,299,1940,13549,99987,768752,6089791, 49392723,408550278,3435528229,29289695650, 252672394234,2201981901415,19360330918473, 171550299264139,1530609037414453] |