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| n | a(n) |
|---|---|
| 1 | 4 |
| 2 | 13 |
| 3 | 33 |
| 4 | 70 |
| 5 | 154 |
| 6 | 433 |
| 7 | 1166 |
| 8 | 3153 |
| 9 | 8468 |
| 10 | 22750 |
| 11 | 61199 |
| 12 | 165177 |
| 13 | 445570 |
| 14 | 1201785 |
| 15 | 3241825 |
| 16 | 8746118 |
| 17 | 23596920 |
| 18 | 63667249 |
| 19 | 171782178 |
| 20 | 463490985 |
| 21 | 1250567970 |
| 22 | 3374237398 |
| 23 | 9104258583 |
| 24 | 24564843989 |
| 25 | 66280181642 |
| 26 | 178835414969 |
| 27 | 482529064189 |
[4,13,33,70,154,433,1166,3153,8468,22750,61199, 165177,445570,1201785,3241825,8746118,23596920, 63667249,171782178,463490985,1250567970, 3374237398,9104258583,24564843989,66280181642, 178835414969,482529064189] |