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| n | a(n) |
|---|---|
| 3 | 1 |
| 4 | 2 |
| 5 | 3 |
| 6 | 9 |
| 7 | 12 |
| 8 | 33 |
| 9 | 75 |
| 10 | 153 |
| 11 | 492 |
| 12 | 987 |
| 13 | 4179 |
| 14 | 13803 |
| 15 | 18444 |
| 16 | 134043 |
| 17 | 282489 |
| 18 | 1013724 |
| 19 | 4289592 |
| 20 | 12582633 |
| 21 | 57495513 |
| 22 | 260628717 |
| 23 | 801621093 |
| 24 | 3307216989 |
| 25 | 5313193818 |
| 26 | 62909521245 |
| 27 | 308935340153 |
| 28 | 611063815284 |
[1,2,3,9,12,33,75,153,492,987,4179,13803,18444, 134043,282489,1013724,4289592,12582633,57495513, 260628717,801621093,3307216989,5313193818, 62909521245,308935340153,611063815284] |