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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 12 |
| 4 | 33 |
| 5 | 86 |
| 6 | 249 |
| 7 | 680 |
| 8 | 2033 |
| 9 | 5722 |
| 10 | 17485 |
| 11 | 50260 |
| 12 | 156033 |
| 13 | 455534 |
| 14 | 1431281 |
| 15 | 4228752 |
| 16 | 13412193 |
| 17 | 40003058 |
| 18 | 127840085 |
| 19 | 384232156 |
| 20 | 1235575201 |
| 21 | 3737280582 |
| 22 | 12080678505 |
| 23 | 36736735672 |
| 24 | 119276490193 |
| 25 | 364372758986 |
| 26 | 1187542872989 |
[1,2,5,12,33,86,249,680,2033,5722,17485,50260, 156033,455534,1431281,4228752,13412193,40003058, 127840085,384232156,1235575201,3737280582, 12080678505,36736735672,119276490193,364372758986, 1187542872989] |