| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 10 |
| 4 | 21 |
| 5 | 42 |
| 6 | 95 |
| 7 | 210 |
| 8 | 510 |
| 9 | 1258 |
| 10 | 3249 |
| 11 | 8538 |
| 12 | 23033 |
| 13 | 62778 |
| 14 | 173451 |
| 15 | 482690 |
| 16 | 1353075 |
| 17 | 3811362 |
| 18 | 10785233 |
| 19 | 30625194 |
| 20 | 87239997 |
| 21 | 249174234 |
| 22 | 713416599 |
| 23 | 2046945138 |
| 24 | 5884580072 |
| 25 | 16946835090 |
| 26 | 48883925865 |
| 27 | 141217957618 |
| 28 | 408519816609 |
| 29 | 1183291934298 |
| 30 | 3431535849811 |
[2,5,10,21,42,95,210,510,1258,3249,8538,23033, 62778,173451,482690,1353075,3811362,10785233, 30625194,87239997,249174234,713416599,2046945138, 5884580072,16946835090,48883925865,141217957618, 408519816609,1183291934298,3431535849811] |