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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 21 |
| 2 | 126 |
| 3 | 462 |
| 4 | 1287 |
| 5 | 3003 |
| 6 | 6188 |
| 7 | 11628 |
| 8 | 20349 |
| 9 | 33649 |
| 10 | 53130 |
| 11 | 80730 |
| 12 | 118755 |
| 13 | 169911 |
| 14 | 237336 |
| 15 | 324632 |
| 16 | 435897 |
| 17 | 575757 |
| 18 | 749398 |
| 19 | 962598 |
| 20 | 1221759 |
| 21 | 1533939 |
| 22 | 1906884 |
| 23 | 2349060 |
| 24 | 2869685 |
| 25 | 3478761 |
| 26 | 4187106 |
| 27 | 5006386 |
| 28 | 5949147 |
| 29 | 7028847 |
| 30 | 8259888 |
| 31 | 9657648 |
| 32 | 11238513 |
[1,21,126,462,1287,3003,6188,11628,20349,33649, 53130,80730,118755,169911,237336,324632,435897, 575757,749398,962598,1221759,1533939,1906884, 2349060,2869685,3478761,4187106,5006386,5949147, 7028847,8259888,9657648,11238513] |