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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 70 |
| 6 | 200 |
| 7 | 481 |
| 8 | 1004 |
| 9 | 1886 |
| 10 | 3270 |
| 11 | 5325 |
| 12 | 8246 |
| 13 | 12254 |
| 14 | 17596 |
| 15 | 24545 |
| 16 | 33400 |
| 17 | 44486 |
| 18 | 58154 |
| 19 | 74781 |
| 20 | 94770 |
| 21 | 118550 |
| 22 | 146576 |
| 23 | 179329 |
| 24 | 217316 |
| 25 | 261070 |
| 26 | 311150 |
| 27 | 368141 |
| 28 | 432654 |
| 29 | 505326 |
| 30 | 586820 |
[1,2,6,21,70,200,481,1004,1886,3270,5325,8246, 12254,17596,24545,33400,44486,58154,74781,94770, 118550,146576,179329,217316,261070,311150,368141, 432654,505326,586820] |