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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 24 |
| 4 | 99 |
| 5 | 383 |
| 6 | 1662 |
| 7 | 6887 |
| 8 | 30424 |
| 9 | 131019 |
| 10 | 586670 |
| 11 | 2581368 |
| 12 | 11680736 |
| 13 | 52145590 |
| 14 | 237672626 |
| 15 | 1072548623 |
| 16 | 4915035993 |
| 17 | 22359367481 |
| 18 | 102919456563 |
| 19 | 471087278575 |
| 20 | 2176372641684 |
| 21 | 10010910854388 |
| 22 | 46390466191967 |
| 23 | 214249259241312 |
| 24 | 995409647245975 |
| 25 | 4612586140509972 |
| 26 | 21478598420867456 |
| 27 | 99809819411171975 |
[1,2,7,24,99,383,1662,6887,30424,131019,586670, 2581368,11680736,52145590,237672626,1072548623, 4915035993,22359367481,102919456563,471087278575, 2176372641684,10010910854388,46390466191967, 214249259241312,995409647245975,4612586140509972, 21478598420867456,99809819411171975] |