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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 20 |
| 5 | 57 |
| 6 | 191 |
| 7 | 631 |
| 8 | 2153 |
| 9 | 7593 |
| 10 | 26985 |
| 11 | 98071 |
| 12 | 361345 |
| 13 | 1338423 |
| 14 | 5051312 |
| 15 | 19068103 |
| 16 | 73036222 |
| 17 | 280693079 |
| 18 | 1086439277 |
| 19 | 4235355213 |
| 20 | 16553722376 |
| 21 | 65194738319 |
| 22 | 257295232507 |
| 23 | 1020928712938 |
| 24 | 4064700477810 |
| 25 | 16231276471048 |
| 26 | 65088461541823 |
| 27 | 261496712860419 |
| 28 | 1054565027693888 |
| 29 | 4261322146852943 |
[1,1,3,6,20,57,191,631,2153,7593,26985,98071, 361345,1338423,5051312,19068103,73036222, 280693079,1086439277,4235355213,16553722376, 65194738319,257295232507,1020928712938, 4064700477810,16231276471048,65088461541823, 261496712860419,1054565027693888,4261322146852943] |