The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 16 |
| 5 | 39 |
| 6 | 91 |
| 7 | 216 |
| 8 | 499 |
| 9 | 1144 |
| 10 | 2651 |
| 11 | 6152 |
| 12 | 14227 |
| 13 | 32904 |
| 14 | 76187 |
| 15 | 176376 |
| 16 | 408179 |
| 17 | 944728 |
| 18 | 2186779 |
| 19 | 5061544 |
| 20 | 11715219 |
| 21 | 27116008 |
| 22 | 62762971 |
| 23 | 145270808 |
| 24 | 336242675 |
| 25 | 778266424 |
| 26 | 1801373403 |
| 27 | 4169451080 |
| 28 | 9650594451 |
| 29 | 22337231432 |
| 30 | 51701672731 |
[1,1,3,6,16,39,91,216,499,1144,2651,6152,14227, 32904,76187,176376,408179,944728,2186779,5061544, 11715219,27116008,62762971,145270808,336242675, 778266424,1801373403,4169451080,9650594451, 22337231432,51701672731] |