| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 18 |
| 7 | 42 |
| 8 | 91 |
| 9 | 208 |
| 10 | 470 |
| 11 | 1089 |
| 12 | 2509 |
| 13 | 5869 |
| 14 | 13730 |
| 15 | 32371 |
| 16 | 76510 |
| 17 | 181708 |
| 18 | 432635 |
| 19 | 1033656 |
| 20 | 2475384 |
| 21 | 5943395 |
| 22 | 14299532 |
| 23 | 34475030 |
| 24 | 83263872 |
| 25 | 201441431 |
| 26 | 488092897 |
| 27 | 1184353643 |
| 28 | 2877611984 |
| 29 | 7000359244 |
| 30 | 17049288304 |
| 31 | 41568056484 |
| 32 | 101449503960 |
| 33 | 247828380511 |
[1,1,2,4,9,18,42,91,208,470,1089,2509,5869,13730, 32371,76510,181708,432635,1033656,2475384,5943395, 14299532,34475030,83263872,201441431,488092897, 1184353643,2877611984,7000359244,17049288304, 41568056484,101449503960,247828380511] |