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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 21 |
| 5 | 73 |
| 6 | 238 |
| 7 | 721 |
| 8 | 2046 |
| 9 | 5501 |
| 10 | 14158 |
| 11 | 35172 |
| 12 | 84895 |
| 13 | 200133 |
| 14 | 462714 |
| 15 | 1052727 |
| 16 | 2363200 |
| 17 | 5245849 |
| 18 | 11535354 |
| 19 | 25163458 |
| 20 | 54518249 |
| 21 | 117424881 |
| 22 | 251631318 |
| 23 | 536828413 |
| 24 | 1140787234 |
| 25 | 2415828037 |
| 26 | 5100146838 |
| 27 | 10737245792 |
| 28 | 22548348403 |
| 29 | 47244338829 |
| 30 | 98783858242 |
| 31 | 206157933027 |
[1,1,2,6,21,73,238,721,2046,5501,14158,35172, 84895,200133,462714,1052727,2363200,5245849, 11535354,25163458,54518249,117424881,251631318, 536828413,1140787234,2415828037,5100146838, 10737245792,22548348403,47244338829,98783858242, 206157933027] |