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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 16 |
| 4 | 121 |
| 5 | 1166 |
| 6 | 13508 |
| 7 | 181616 |
| 8 | 2769085 |
| 9 | 47109136 |
| 10 | 883639920 |
| 11 | 18107148225 |
| 12 | 402374973506 |
| 13 | 9637795235498 |
| 14 | 247545497301618 |
| 15 | 6787859682565805 |
| 16 | 197933312666622029 |
| 17 | 6116627434424525916 |
| 18 | 199695744998600583128 |
| 19 | 6868763166262716491823 |
| 20 | 248281343442023732418598 |
[1,1,3,16,121,1166,13508,181616,2769085,47109136, 883639920,18107148225,402374973506,9637795235498, 247545497301618,6787859682565805, 197933312666622029,6116627434424525916, 199695744998600583128,6868763166262716491823, 248281343442023732418598] |