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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 20 |
| 4 | 65 |
| 5 | 186 |
| 6 | 462 |
| 7 | 1016 |
| 8 | 2025 |
| 9 | 3730 |
| 10 | 6446 |
| 11 | 10572 |
| 12 | 16601 |
| 13 | 25130 |
| 14 | 36870 |
| 15 | 52656 |
| 16 | 73457 |
| 17 | 100386 |
| 18 | 134710 |
| 19 | 177860 |
| 20 | 231441 |
| 21 | 297242 |
| 22 | 377246 |
| 23 | 473640 |
| 24 | 588825 |
| 25 | 725426 |
| 26 | 886302 |
| 27 | 1074556 |
| 28 | 1293545 |
| 29 | 1546890 |
| 30 | 1838486 |
| 31 | 2172512 |
| 32 | 2553441 |
| 33 | 2986050 |
| 34 | 3475430 |
| 35 | 4026996 |
[1,2,6,20,65,186,462,1016,2025,3730,6446,10572, 16601,25130,36870,52656,73457,100386,134710, 177860,231441,297242,377246,473640,588825,725426, 886302,1074556,1293545,1546890,1838486,2172512, 2553441,2986050,3475430,4026996] |