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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 22 |
| 5 | 61 |
| 6 | 233 |
| 7 | 733 |
| 8 | 2947 |
| 9 | 10104 |
| 10 | 41604 |
| 11 | 150819 |
| 12 | 634383 |
| 13 | 2395210 |
| 14 | 10223510 |
| 15 | 39801121 |
| 16 | 171943819 |
| 17 | 685615395 |
| 18 | 2990420051 |
| 19 | 12155736895 |
| 20 | 53444047859 |
| 21 | 220699421489 |
| 22 | 976862543867 |
| 23 | 4087516321436 |
| 24 | 18196407921064 |
| 25 | 76994974494165 |
| 26 | 344467263811475 |
| 27 | 1471591422477907 |
| 28 | 6612456796697229 |
[1,1,3,6,22,61,233,733,2947,10104,41604,150819, 634383,2395210,10223510,39801121,171943819, 685615395,2990420051,12155736895,53444047859, 220699421489,976862543867,4087516321436, 18196407921064,76994974494165,344467263811475, 1471591422477907,6612456796697229] |