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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 32 |
| 5 | 145 |
| 6 | 681 |
| 7 | 3337 |
| 8 | 16773 |
| 9 | 86181 |
| 10 | 450268 |
| 11 | 2385544 |
| 12 | 12784861 |
| 13 | 69189509 |
| 14 | 377576512 |
| 15 | 2075423744 |
| 16 | 11480230037 |
| 17 | 63857579629 |
| 18 | 356962271136 |
| 19 | 2004255583560 |
| 20 | 11298268724556 |
| 21 | 63919517790933 |
| 22 | 362806671879955 |
| 23 | 2065443363987045 |
| 24 | 11790688867079872 |
| 25 | 67477283970889867 |
[1,1,2,8,32,145,681,3337,16773,86181,450268, 2385544,12784861,69189509,377576512,2075423744, 11480230037,63857579629,356962271136, 2004255583560,11298268724556,63919517790933, 362806671879955,2065443363987045, 11790688867079872,67477283970889867] |