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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 28 |
| 4 | 80 |
| 5 | 200 |
| 6 | 469 |
| 7 | 1064 |
| 8 | 2359 |
| 9 | 5144 |
| 10 | 11091 |
| 11 | 23739 |
| 12 | 50569 |
| 13 | 107380 |
| 14 | 227518 |
| 15 | 481337 |
| 16 | 1017225 |
| 17 | 2148079 |
| 18 | 4533560 |
| 19 | 9564187 |
| 20 | 20170750 |
| 21 | 42529933 |
| 22 | 89658336 |
| 23 | 188985456 |
| 24 | 398310426 |
| 25 | 839423323 |
| 26 | 1768945377 |
| 27 | 3727588148 |
| 28 | 7854637968 |
| 29 | 16550561260 |
[1,7,28,80,200,469,1064,2359,5144,11091,23739, 50569,107380,227518,481337,1017225,2148079, 4533560,9564187,20170750,42529933,89658336, 188985456,398310426,839423323,1768945377, 3727588148,7854637968,16550561260] |