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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 5 |
| 3 | 19 |
| 4 | 215 |
| 5 | 3221 |
| 6 | 60255 |
| 7 | 1328529 |
| 8 | 33525557 |
| 9 | 949932155 |
| 10 | 29820028655 |
| 11 | 1026798211345 |
| 12 | 38478492170097 |
| 13 | 1559272992752559 |
| 14 | 67959179777259427 |
| 15 | 3170787800382000429 |
| 16 | 157723858411070076821 |
| 17 | 8334021579932292731707 |
| 18 | 466249346920348934320021 |
| 19 | 27536331208734157654465035 |
| 20 | 1712202839967112789793314087 |
| 21 | 111816679758439520925160452089 |
[1,1,5,19,215,3221,60255,1328529,33525557, 949932155,29820028655,1026798211345, 38478492170097,1559272992752559,67959179777259427, 3170787800382000429,157723858411070076821, 8334021579932292731707,466249346920348934320021, 27536331208734157654465035, 1712202839967112789793314087, 111816679758439520925160452089] |