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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 11 |
| 4 | 33 |
| 5 | 64 |
| 6 | 191 |
| 7 | 376 |
| 8 | 1122 |
| 9 | 2222 |
| 10 | 6636 |
| 11 | 13180 |
| 12 | 39395 |
| 13 | 78373 |
| 14 | 234414 |
| 15 | 466840 |
| 16 | 1397034 |
| 17 | 2784266 |
| 18 | 8335242 |
| 19 | 16620976 |
| 20 | 49773018 |
| 21 | 99291358 |
| 22 | 297406884 |
| 23 | 593484440 |
| 24 | 1777995535 |
| 25 | 3548969075 |
| 26 | 10633840743 |
| 27 | 21230215328 |
| 28 | 63620551947 |
[1,2,6,11,33,64,191,376,1122,2222,6636,13180, 39395,78373,234414,466840,1397034,2784266,8335242, 16620976,49773018,99291358,297406884,593484440, 1777995535,3548969075,10633840743,21230215328, 63620551947] |