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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 10 |
| 5 | 32 |
| 6 | 102 |
| 7 | 326 |
| 8 | 1046 |
| 9 | 3370 |
| 10 | 10899 |
| 11 | 35369 |
| 12 | 115123 |
| 13 | 375705 |
| 14 | 1228970 |
| 15 | 4028366 |
| 16 | 13228516 |
| 17 | 43511464 |
| 18 | 143329157 |
| 19 | 472761015 |
| 20 | 1561246112 |
| 21 | 5161512902 |
| 22 | 17081176912 |
| 23 | 56579333508 |
| 24 | 187570898065 |
| 25 | 622318325281 |
| 26 | 2066208751201 |
| 27 | 6864800067363 |
| 28 | 22821993704857 |
| 29 | 75915970992635 |
| 30 | 252667993114760 |
[1,3,10,32,102,326,1046,3370,10899,35369,115123, 375705,1228970,4028366,13228516,43511464, 143329157,472761015,1561246112,5161512902, 17081176912,56579333508,187570898065,622318325281, 2066208751201,6864800067363,22821993704857, 75915970992635,252667993114760] |