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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 3 |
| 6 | 29 |
| 7 | 286 |
| 8 | 1252 |
| 9 | 5910 |
| 10 | 18058 |
| 11 | 59820 |
| 12 | 147057 |
| 13 | 385126 |
| 14 | 808153 |
| 15 | 1819415 |
| 16 | 3419890 |
| 17 | 6872235 |
| 18 | 11853812 |
| 19 | 21945574 |
| 20 | 35503801 |
| 21 | 61441639 |
| 22 | 94283546 |
| 23 | 155139350 |
| 24 | 227922254 |
| 25 | 359372638 |
| 26 | 509599423 |
| 27 | 774249654 |
| 28 | 1067712369 |
| 29 | 1574987136 |
[0,0,0,0,3,29,286,1252,5910,18058,59820,147057, 385126,808153,1819415,3419890,6872235,11853812, 21945574,35503801,61441639,94283546,155139350, 227922254,359372638,509599423,774249654, 1067712369,1574987136] |