The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 2 |
| 1 | 20 |
| 2 | 174 |
| 3 | 1504 |
| 4 | 13300 |
| 5 | 120744 |
| 6 | 1122198 |
| 7 | 10638464 |
| 8 | 102541428 |
| 9 | 1002305040 |
| 10 | 9914663308 |
| 11 | 99085515840 |
| 12 | 999104604784 |
| 13 | 10153152363648 |
| 14 | 103892246982390 |
| 15 | 1069610792999424 |
| 16 | 11072575568623300 |
| 17 | 115189593628215600 |
[2,20,174,1504,13300,120744,1122198,10638464, 102541428,1002305040,9914663308,99085515840, 999104604784,10153152363648,103892246982390, 1069610792999424,11072575568623300, 115189593628215600] |