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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 10 |
| 4 | 70 |
| 5 | 126 |
| 6 | 462 |
| 7 | 858 |
| 8 | 12870 |
| 9 | 24310 |
| 10 | 92378 |
| 11 | 176358 |
| 12 | 1352078 |
| 13 | 2600150 |
| 14 | 10029150 |
| 15 | 19389690 |
| 16 | 601080390 |
| 17 | 1166803110 |
| 18 | 4537567650 |
| 19 | 8836315950 |
| 20 | 68923264410 |
| 21 | 134564468610 |
| 22 | 526024740930 |
| 23 | 1029178840950 |
| 24 | 16123801841550 |
| 25 | 31602651609438 |
| 26 | 123979633237026 |
[2,6,10,70,126,462,858,12870,24310,92378,176358, 1352078,2600150,10029150,19389690,601080390, 1166803110,4537567650,8836315950,68923264410, 134564468610,526024740930,1029178840950, 16123801841550,31602651609438,123979633237026] |