The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 14 |
| 4 | 182 |
| 5 | 2364 |
| 6 | 36020 |
| 7 | 513774 |
| 8 | 7466956 |
| 9 | 108082822 |
| 10 | 1565657608 |
| 11 | 22676496408 |
| 12 | 328443902490 |
| 13 | 4757195184330 |
| 14 | 68903138021262 |
| 15 | 997992766403828 |
| 16 | 14454923305122306 |
| 17 | 209365029835258358 |
| 18 | 3032442137209416056 |
[0,2,14,182,2364,36020,513774,7466956,108082822, 1565657608,22676496408,328443902490,4757195184330, 68903138021262,997992766403828,14454923305122306, 209365029835258358,3032442137209416056] |