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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 6 |
| 3 | 19 |
| 4 | 61 |
| 5 | 191 |
| 6 | 588 |
| 7 | 1785 |
| 8 | 5351 |
| 9 | 15868 |
| 10 | 46628 |
| 11 | 135921 |
| 12 | 393318 |
| 13 | 1130538 |
| 14 | 3229753 |
| 15 | 9175347 |
| 16 | 25931605 |
| 17 | 72936434 |
| 18 | 204223348 |
| 19 | 569427145 |
| 20 | 1581458917 |
| 21 | 4375905243 |
| 22 | 12065914843 |
| 23 | 33160240020 |
| 24 | 90848002909 |
| 25 | 248154744196 |
| 26 | 675932128695 |
| 27 | 1836182233332 |
| 28 | 4975249827916 |
| 29 | 13447775233746 |
[1,2,6,19,61,191,588,1785,5351,15868,46628,135921, 393318,1130538,3229753,9175347,25931605,72936434, 204223348,569427145,1581458917,4375905243, 12065914843,33160240020,90848002909,248154744196, 675932128695,1836182233332,4975249827916, 13447775233746] |