The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 16 |
| 3 | 90 |
| 4 | 760 |
| 5 | 5200 |
| 6 | 46956 |
| 7 | 370734 |
| 8 | 3599104 |
| 9 | 31807710 |
| 10 | 329885620 |
| 11 | 3198732768 |
| 12 | 35206521816 |
| 13 | 369188811082 |
| 14 | 4287997640080 |
| 15 | 48104913781890 |
| 16 | 586813738039904 |
| 17 | 6984278125524784 |
| 18 | 89124296743065348 |
| 19 | 1118012637781250310 |
[2,16,90,760,5200,46956,370734,3599104,31807710, 329885620,3198732768,35206521816,369188811082, 4287997640080,48104913781890,586813738039904, 6984278125524784,89124296743065348, 1118012637781250310] |