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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 22 |
| 5 | 92 |
| 6 | 402 |
| 7 | 1832 |
| 8 | 8453 |
| 9 | 39640 |
| 10 | 186296 |
| 11 | 881147 |
| 12 | 4162866 |
| 13 | 19721230 |
| 14 | 93250730 |
| 15 | 441549914 |
| 16 | 2086950250 |
| 17 | 9872284420 |
| 18 | 46627034590 |
| 19 | 220354970198 |
| 20 | 1040000436047 |
| 21 | 4910777435839 |
| 22 | 23162527440081 |
| 23 | 109292500313185 |
| 24 | 515214985932766 |
[1,2,6,22,92,402,1832,8453,39640,186296,881147, 4162866,19721230,93250730,441549914,2086950250, 9872284420,46627034590,220354970198,1040000436047, 4910777435839,23162527440081,109292500313185, 515214985932766] |