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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 8 |
| 3 | 22 |
| 4 | 59 |
| 5 | 157 |
| 6 | 418 |
| 7 | 1112 |
| 8 | 2957 |
| 9 | 7863 |
| 10 | 20908 |
| 11 | 55594 |
| 12 | 147823 |
| 13 | 393057 |
| 14 | 1045126 |
| 15 | 2778956 |
| 16 | 7389153 |
| 17 | 19647515 |
| 18 | 52242096 |
| 19 | 138910014 |
| 20 | 369357155 |
| 21 | 982108517 |
| 22 | 2611394218 |
| 23 | 6943611264 |
| 24 | 18462833781 |
| 25 | 49092067263 |
| 26 | 130534190836 |
| 27 | 347086116498 |
| 28 | 922890558359 |
| 29 | 2453935614889 |
[1,3,8,22,59,157,418,1112,2957,7863,20908,55594, 147823,393057,1045126,2778956,7389153,19647515, 52242096,138910014,369357155,982108517,2611394218, 6943611264,18462833781,49092067263,130534190836, 347086116498,922890558359,2453935614889] |