The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 11 |
| 3 | 72 |
| 4 | 734 |
| 5 | 6994 |
| 6 | 74641 |
| 7 | 803196 |
| 8 | 8989482 |
| 9 | 102192197 |
| 10 | 1184211027 |
| 11 | 13897707080 |
| 12 | 165052834584 |
| 13 | 1978844990494 |
| 14 | 23924151189858 |
| 15 | 291313067897212 |
| 16 | 3569576082827250 |
| 17 | 43981925261314302 |
| 18 | 544590342185545146 |
| 19 | 6772925262506494672 |
| 20 | 84567358373934285042 |
[1,1,11,72,734,6994,74641,803196,8989482, 102192197,1184211027,13897707080,165052834584, 1978844990494,23924151189858,291313067897212, 3569576082827250,43981925261314302, 544590342185545146,6772925262506494672, 84567358373934285042] |