The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 15 |
| 2 | 46 |
| 3 | 146 |
| 4 | 621 |
| 5 | 2190 |
| 6 | 6965 |
| 7 | 21035 |
| 8 | 60891 |
| 9 | 171009 |
| 10 | 465323 |
| 11 | 1225425 |
| 12 | 3124293 |
| 13 | 7723032 |
| 14 | 18545881 |
| 15 | 43355303 |
| 16 | 98866072 |
| 17 | 220320615 |
| 18 | 480589189 |
| 19 | 1027625310 |
| 20 | 2156754843 |
| 21 | 4448124037 |
| 22 | 9024377209 |
| 23 | 18027331364 |
| 24 | 35488683485 |
| 25 | 68901443927 |
[15,46,146,621,2190,6965,21035,60891,171009, 465323,1225425,3124293,7723032,18545881,43355303, 98866072,220320615,480589189,1027625310, 2156754843,4448124037,9024377209,18027331364, 35488683485,68901443927] |