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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 35 |
| 3 | 446 |
| 4 | 2827 |
| 5 | 13686 |
| 6 | 59859 |
| 7 | 250198 |
| 8 | 1023347 |
| 9 | 4140830 |
| 10 | 16663627 |
| 11 | 66867438 |
| 12 | 267922683 |
| 13 | 1072654438 |
| 14 | 4292666147 |
| 15 | 17175010598 |
| 16 | 68709242467 |
| 17 | 274856398542 |
| 18 | 1099466524251 |
| 19 | 4397952122110 |
| 20 | 17591988892331 |
| 21 | 70368333113174 |
[4,35,446,2827,13686,59859,250198,1023347,4140830, 16663627,66867438,267922683,1072654438,4292666147, 17175010598,68709242467,274856398542, 1099466524251,4397952122110,17591988892331, 70368333113174] |