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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 6 |
| 6 | 12 |
| 7 | 31 |
| 8 | 68 |
| 9 | 186 |
| 10 | 506 |
| 11 | 1299 |
| 12 | 3481 |
| 13 | 9712 |
| 14 | 27692 |
| 15 | 79587 |
| 16 | 232743 |
| 17 | 694896 |
| 18 | 2086245 |
| 19 | 6248158 |
| 20 | 18771510 |
| 21 | 57007483 |
| 22 | 175149700 |
| 23 | 542313513 |
| 24 | 1688360997 |
| 25 | 5288335561 |
| 26 | 16679137617 |
| 27 | 52933231538 |
| 28 | 168768966207 |
| 29 | 539981776609 |
| 30 | 1733555552587 |
| 31 | 5587076558809 |
[1,1,1,1,3,6,12,31,68,186,506,1299,3481,9712, 27692,79587,232743,694896,2086245,6248158, 18771510,57007483,175149700,542313513,1688360997, 5288335561,16679137617,52933231538,168768966207, 539981776609,1733555552587,5587076558809] |