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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 18 |
| 5 | 59 |
| 6 | 210 |
| 7 | 771 |
| 8 | 2996 |
| 9 | 11644 |
| 10 | 46638 |
| 11 | 190413 |
| 12 | 785883 |
| 13 | 3269350 |
| 14 | 13802880 |
| 15 | 58805780 |
| 16 | 251800165 |
| 17 | 1085863136 |
| 18 | 4718853763 |
| 19 | 20599960049 |
| 20 | 90292141257 |
| 21 | 397829888521 |
| 22 | 1760283533023 |
| 23 | 7811722003196 |
| 24 | 34783756873350 |
| 25 | 155429698073397 |
| 26 | 696354098036891 |
| 27 | 3127128078447276 |
| 28 | 14080315363387703 |
[1,1,2,5,18,59,210,771,2996,11644,46638,190413, 785883,3269350,13802880,58805780,251800165, 1085863136,4718853763,20599960049,90292141257, 397829888521,1760283533023,7811722003196, 34783756873350,155429698073397,696354098036891, 3127128078447276,14080315363387703] |