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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 16 |
| 3 | 157 |
| 4 | 1254 |
| 5 | 9068 |
| 6 | 62617 |
| 7 | 426022 |
| 8 | 2913894 |
| 9 | 20307833 |
| 10 | 145503003 |
| 11 | 1077731960 |
| 12 | 8277491943 |
| 13 | 66003259942 |
| 14 | 546398875027 |
| 15 | 4692545543444 |
| 16 | 41760563809046 |
| 17 | 384605668021029 |
| 18 | 3660788725969481 |
| 19 | 35964832246977675 |
| 20 | 364242679197958081 |
[1,16,157,1254,9068,62617,426022,2913894,20307833, 145503003,1077731960,8277491943,66003259942, 546398875027,4692545543444,41760563809046, 384605668021029,3660788725969481, 35964832246977675,364242679197958081] |