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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 12 |
| 3 | 110 |
| 4 | 1368 |
| 5 | 21602 |
| 6 | 415036 |
| 7 | 9416094 |
| 8 | 246730448 |
| 9 | 7340456258 |
| 10 | 244615296564 |
| 11 | 9030708939518 |
| 12 | 365998814372824 |
| 13 | 16159576541122146 |
| 14 | 772216069907880812 |
| 15 | 39715949460883093598 |
| 16 | 2187682975276318552224 |
| 17 | 128508919233259720967810 |
[1,2,12,110,1368,21602,415036,9416094,246730448, 7340456258,244615296564,9030708939518, 365998814372824,16159576541122146, 772216069907880812,39715949460883093598, 2187682975276318552224,128508919233259720967810] |