The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 12 |
| 2 | 30 |
| 3 | 72 |
| 4 | 174 |
| 5 | 422 |
| 6 | 1028 |
| 7 | 2510 |
| 8 | 6134 |
| 9 | 14988 |
| 10 | 36594 |
| 11 | 89250 |
| 12 | 217416 |
| 13 | 529010 |
| 14 | 1285754 |
| 15 | 3121904 |
| 16 | 7573550 |
| 17 | 18358950 |
| 18 | 44474532 |
| 19 | 107679342 |
| 20 | 260584230 |
| 21 | 630363356 |
| 22 | 1524363938 |
| 23 | 3685232642 |
| 24 | 8907169352 |
| 25 | 21524344338 |
| 26 | 52005554058 |
| 27 | 125635087296 |
[12,30,72,174,422,1028,2510,6134,14988,36594, 89250,217416,529010,1285754,3121904,7573550, 18358950,44474532,107679342,260584230,630363356, 1524363938,3685232642,8907169352,21524344338, 52005554058,125635087296] |