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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 3 |
| 3 | 6 |
| 4 | 13 |
| 5 | 28 |
| 6 | 62 |
| 7 | 144 |
| 8 | 338 |
| 9 | 810 |
| 10 | 1970 |
| 11 | 4852 |
| 12 | 12073 |
| 13 | 30334 |
| 14 | 76805 |
| 15 | 195850 |
| 16 | 502461 |
| 17 | 1296122 |
| 18 | 3359527 |
| 19 | 8745744 |
| 20 | 22856223 |
| 21 | 59944156 |
| 22 | 157718380 |
| 23 | 416189954 |
| 24 | 1101204387 |
| 25 | 2920914484 |
| 26 | 7765357967 |
| 27 | 20688204244 |
| 28 | 55225188289 |
| 29 | 147688302518 |
[1,2,3,6,13,28,62,144,338,810,1970,4852,12073, 30334,76805,195850,502461,1296122,3359527,8745744, 22856223,59944156,157718380,416189954,1101204387, 2920914484,7765357967,20688204244,55225188289, 147688302518] |