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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 50 |
| 6 | 183 |
| 7 | 612 |
| 8 | 2427 |
| 9 | 8825 |
| 10 | 36059 |
| 11 | 138389 |
| 12 | 581717 |
| 13 | 2316687 |
| 14 | 9922307 |
| 15 | 40628935 |
| 16 | 176649853 |
| 17 | 738938555 |
| 18 | 3250269764 |
| 19 | 13829300753 |
| 20 | 61402897922 |
| 21 | 264875758505 |
| 22 | 1185178057988 |
| 23 | 5170848320772 |
| 24 | 23286936959696 |
| 25 | 102567165143373 |
| 26 | 464457815281869 |
| 27 | 2062198363246999 |
| 28 | 9382546018637717 |
[1,1,2,5,17,50,183,612,2427,8825,36059,138389, 581717,2316687,9922307,40628935,176649853, 738938555,3250269764,13829300753,61402897922, 264875758505,1185178057988,5170848320772, 23286936959696,102567165143373,464457815281869, 2062198363246999,9382546018637717] |