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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 18 |
| 4 | 42 |
| 5 | 102 |
| 6 | 238 |
| 7 | 522 |
| 8 | 1130 |
| 9 | 2394 |
| 10 | 4926 |
| 11 | 9978 |
| 12 | 19890 |
| 13 | 38942 |
| 14 | 75254 |
| 15 | 143598 |
| 16 | 270506 |
| 17 | 504126 |
| 18 | 929926 |
| 19 | 1698322 |
| 20 | 3074010 |
| 21 | 5516898 |
| 22 | 9820550 |
| 23 | 17349554 |
| 24 | 30430610 |
| 25 | 53007162 |
| 26 | 91734262 |
| 27 | 157771538 |
| 28 | 269734714 |
| 29 | 458542822 |
| 30 | 775281982 |
| 31 | 1303971722 |
| 32 | 2182227546 |
| 33 | 3634444634 |
[1,2,6,18,42,102,238,522,1130,2394,4926,9978, 19890,38942,75254,143598,270506,504126,929926, 1698322,3074010,5516898,9820550,17349554,30430610, 53007162,91734262,157771538,269734714,458542822, 775281982,1303971722,2182227546,3634444634] |