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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 10 |
| 4 | 18 |
| 5 | 38 |
| 6 | 84 |
| 7 | 186 |
| 8 | 410 |
| 9 | 904 |
| 10 | 1994 |
| 11 | 4398 |
| 12 | 9700 |
| 13 | 21394 |
| 14 | 47186 |
| 15 | 104072 |
| 16 | 229538 |
| 17 | 506262 |
| 18 | 1116596 |
| 19 | 2462730 |
| 20 | 5431722 |
| 21 | 11980040 |
| 22 | 26422810 |
| 23 | 58277342 |
| 24 | 128534724 |
| 25 | 283492258 |
| 26 | 625261858 |
| 27 | 1379058440 |
| 28 | 3041609138 |
| 29 | 6708480134 |
| 30 | 14796018708 |
| 31 | 32633646554 |
| 32 | 71975773242 |
[2,6,10,18,38,84,186,410,904,1994,4398,9700,21394, 47186,104072,229538,506262,1116596,2462730, 5431722,11980040,26422810,58277342,128534724, 283492258,625261858,1379058440,3041609138, 6708480134,14796018708,32633646554,71975773242] |