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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 24 |
| 5 | 84 |
| 6 | 315 |
| 7 | 1225 |
| 8 | 4859 |
| 9 | 19646 |
| 10 | 80739 |
| 11 | 336050 |
| 12 | 1413587 |
| 13 | 6000777 |
| 14 | 25674462 |
| 15 | 110598855 |
| 16 | 479286932 |
| 17 | 2088036939 |
| 18 | 9139604421 |
| 19 | 40174594432 |
| 20 | 177267942918 |
| 21 | 784889441217 |
| 22 | 3486198469890 |
| 23 | 15529021825140 |
| 24 | 69355660644738 |
| 25 | 310509670642611 |
| 26 | 1393296782758244 |
[1,1,2,7,24,84,315,1225,4859,19646,80739,336050, 1413587,6000777,25674462,110598855,479286932, 2088036939,9139604421,40174594432,177267942918, 784889441217,3486198469890,15529021825140, 69355660644738,310509670642611,1393296782758244] |