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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 27 |
| 5 | 67 |
| 6 | 193 |
| 7 | 515 |
| 8 | 1462 |
| 9 | 4070 |
| 10 | 11588 |
| 11 | 32898 |
| 12 | 94389 |
| 13 | 271017 |
| 14 | 782401 |
| 15 | 2263002 |
| 16 | 6565987 |
| 17 | 19086043 |
| 18 | 55597255 |
| 19 | 162207806 |
| 20 | 473992799 |
| 21 | 1386875848 |
| 22 | 4062919108 |
| 23 | 11915397853 |
| 24 | 34979609583 |
| 25 | 102781548770 |
| 26 | 302259362326 |
| 27 | 889566748760 |
| 28 | 2619915414564 |
| 29 | 7721166976185 |
[1,1,4,9,27,67,193,515,1462,4070,11588,32898, 94389,271017,782401,2263002,6565987,19086043, 55597255,162207806,473992799,1386875848, 4062919108,11915397853,34979609583,102781548770, 302259362326,889566748760,2619915414564, 7721166976185] |