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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 31 |
| 4 | 157 |
| 5 | 188 |
| 6 | 909 |
| 7 | 2006 |
| 8 | 2915 |
| 9 | 4921 |
| 10 | 17678 |
| 11 | 22599 |
| 12 | 62876 |
| 13 | 399855 |
| 14 | 862586 |
| 15 | 1262441 |
| 16 | 4649909 |
| 17 | 5912350 |
| 18 | 10562259 |
| 19 | 27036868 |
| 20 | 118709731 |
| 21 | 145746599 |
| 22 | 847442726 |
| 23 | 12857387489 |
| 24 | 13704830215 |
| 25 | 26562217704 |
| 26 | 1235566844599 |
| 27 | 1262129062303 |
| 28 | 2497695906902 |
| 29 | 38727567665833 |
[1,1,2,31,157,188,909,2006,2915,4921,17678,22599, 62876,399855,862586,1262441,4649909,5912350, 10562259,27036868,118709731,145746599,847442726, 12857387489,13704830215,26562217704,1235566844599, 1262129062303,2497695906902,38727567665833] |