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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 9 |
| 3 | 34 |
| 4 | 105 |
| 5 | 286 |
| 6 | 721 |
| 7 | 1730 |
| 8 | 4017 |
| 9 | 9118 |
| 10 | 20361 |
| 11 | 44914 |
| 12 | 98137 |
| 13 | 212798 |
| 14 | 458529 |
| 15 | 982786 |
| 16 | 2096865 |
| 17 | 4456126 |
| 18 | 9436825 |
| 19 | 19922546 |
| 20 | 41942601 |
| 21 | 88079902 |
| 22 | 184548849 |
| 23 | 385875394 |
| 24 | 805305745 |
| 25 | 1677720926 |
| 26 | 3489660201 |
| 27 | 7247756530 |
| 28 | 15032384697 |
| 29 | 31138511998 |
| 30 | 64424508481 |
[2,9,34,105,286,721,1730,4017,9118,20361,44914, 98137,212798,458529,982786,2096865,4456126, 9436825,19922546,41942601,88079902,184548849, 385875394,805305745,1677720926,3489660201, 7247756530,15032384697,31138511998,64424508481] |