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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | 1 |
| 12 | 6 |
| 13 | 21 |
| 14 | 56 |
| 15 | 126 |
| 16 | 252 |
| 17 | 463 |
| 18 | 810 |
| 19 | 1464 |
| 20 | 3262 |
| 21 | 10269 |
| 22 | 40404 |
| 23 | 165635 |
| 24 | 653580 |
| 25 | 2439069 |
| 26 | 8626470 |
| 27 | 29121393 |
| 28 | 94647798 |
| 29 | 299273206 |
| 30 | 933818700 |
| 31 | 2935248294 |
| 32 | 9557815564 |
| 33 | 33225405312 |
| 34 | 125646127446 |
| 35 | 514785555355 |
| 36 | 2232901148760 |
| 37 | 9976014439674 |
| 38 | 44944467146100 |
| 39 | 201608952292578 |
| 40 | 895062795448170 |
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