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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 11 |
| 3 | 40 |
| 4 | 124 |
| 5 | 367 |
| 6 | 1070 |
| 7 | 3104 |
| 8 | 8989 |
| 9 | 26016 |
| 10 | 75280 |
| 11 | 217815 |
| 12 | 630210 |
| 13 | 1823388 |
| 14 | 5275597 |
| 15 | 15263836 |
| 16 | 44162700 |
| 17 | 127775471 |
| 18 | 369691398 |
| 19 | 1069624136 |
| 20 | 3094731965 |
| 21 | 8953954568 |
| 22 | 25906380024 |
| 23 | 74954649447 |
| 24 | 216865477466 |
| 25 | 627454543012 |
| 26 | 1815407450477 |
| 27 | 5252498763364 |
| 28 | 15196997925652 |
[1,11,40,124,367,1070,3104,8989,26016,75280, 217815,630210,1823388,5275597,15263836,44162700, 127775471,369691398,1069624136,3094731965, 8953954568,25906380024,74954649447,216865477466, 627454543012,1815407450477,5252498763364, 15196997925652] |