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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 18 |
| 5 | 47 |
| 6 | 146 |
| 7 | 437 |
| 8 | 1451 |
| 9 | 4668 |
| 10 | 16319 |
| 11 | 55099 |
| 12 | 198142 |
| 13 | 694725 |
| 14 | 2550044 |
| 15 | 9196709 |
| 16 | 34419107 |
| 17 | 126786769 |
| 18 | 482259784 |
| 19 | 1807496942 |
| 20 | 6961192206 |
| 21 | 26474866175 |
| 22 | 103031786721 |
| 23 | 396643062709 |
| 24 | 1558079024775 |
| 25 | 6059890716650 |
| 26 | 23997891168321 |
| 27 | 94170491451715 |
| 28 | 375529653219883 |
| 29 | 1485175637380365 |
| 30 | 5959097542175507 |
[1,1,3,6,18,47,146,437,1451,4668,16319,55099, 198142,694725,2550044,9196709,34419107,126786769, 482259784,1807496942,6961192206,26474866175, 103031786721,396643062709,1558079024775, 6059890716650,23997891168321,94170491451715, 375529653219883,1485175637380365,5959097542175507] |