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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 4 |
| 3 | 17 |
| 4 | 75 |
| 5 | 339 |
| 6 | 1558 |
| 7 | 7247 |
| 8 | 34016 |
| 9 | 160795 |
| 10 | 764388 |
| 11 | 3650571 |
| 12 | 17501619 |
| 13 | 84179877 |
| 14 | 406020930 |
| 15 | 1963073865 |
| 16 | 9511333155 |
| 17 | 46169418195 |
| 18 | 224484046660 |
| 19 | 1093097083475 |
| 20 | 5329784874185 |
| 21 | 26018549129545 |
| 22 | 127154354598330 |
| 23 | 622031993807565 |
[1,4,17,75,339,1558,7247,34016,160795,764388, 3650571,17501619,84179877,406020930,1963073865, 9511333155,46169418195,224484046660,1093097083475, 5329784874185,26018549129545,127154354598330, 622031993807565] |