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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 8 |
| 3 | 30 |
| 4 | 126 |
| 5 | 530 |
| 6 | 2330 |
| 7 | 10290 |
| 8 | 46410 |
| 9 | 210462 |
| 10 | 966042 |
| 11 | 4455066 |
| 12 | 20703606 |
| 13 | 96597930 |
| 14 | 453102078 |
| 15 | 2132350506 |
| 16 | 10074190698 |
| 17 | 47726505398 |
| 18 | 226781353370 |
| 19 | 1080087917766 |
| 20 | 5156365273202 |
| 21 | 24664826475302 |
| 22 | 118210918387146 |
| 23 | 567495368954410 |
| 24 | 2728811135183302 |
| 25 | 13140420242879490 |
| 26 | 63364479984294270 |
[1,2,8,30,126,530,2330,10290,46410,210462,966042, 4455066,20703606,96597930,453102078,2132350506, 10074190698,47726505398,226781353370, 1080087917766,5156365273202,24664826475302, 118210918387146,567495368954410,2728811135183302, 13140420242879490,63364479984294270] |