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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 28 |
| 4 | 206 |
| 5 | 1786 |
| 6 | 18347 |
| 7 | 212745 |
| 8 | 2773927 |
| 9 | 39901109 |
| 10 | 628298992 |
| 11 | 10725440221 |
| 12 | 197349522471 |
| 13 | 3888090474399 |
| 14 | 81659016005387 |
| 15 | 1820049574958950 |
| 16 | 42895622543757084 |
| 17 | 1065460090285463634 |
| 18 | 27811791343693345811 |
| 19 | 760920657403831436463 |
[1,1,5,28,206,1786,18347,212745,2773927,39901109, 628298992,10725440221,197349522471,3888090474399, 81659016005387,1820049574958950,42895622543757084, 1065460090285463634,27811791343693345811, 760920657403831436463] |