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| n | a(n) |
|---|---|
| 2 | 3 |
| 3 | 9 |
| 4 | 20 |
| 5 | 40 |
| 6 | 77 |
| 7 | 145 |
| 8 | 270 |
| 9 | 500 |
| 10 | 923 |
| 11 | 1701 |
| 12 | 3132 |
| 13 | 5764 |
| 14 | 10605 |
| 15 | 19509 |
| 16 | 35886 |
| 17 | 66008 |
| 18 | 121411 |
| 19 | 223313 |
| 20 | 410740 |
| 21 | 755472 |
| 22 | 1389533 |
| 23 | 2555753 |
| 24 | 4700766 |
| 25 | 8646060 |
| 26 | 15902587 |
| 27 | 29249421 |
| 28 | 53798076 |
| 29 | 98950092 |
| 30 | 181997597 |
| 31 | 334745773 |
| 32 | 615693470 |
[3,9,20,40,77,145,270,500,923,1701,3132,5764, 10605,19509,35886,66008,121411,223313,410740, 755472,1389533,2555753,4700766,8646060,15902587, 29249421,53798076,98950092,181997597,334745773, 615693470] |