The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 11 |
| 2 | 90 |
| 3 | 670 |
| 4 | 4811 |
| 5 | 34041 |
| 6 | 239380 |
| 7 | 1678940 |
| 8 | 11762421 |
| 9 | 82366471 |
| 10 | 576653870 |
| 11 | 4036842810 |
| 12 | 28258696831 |
| 13 | 197813269301 |
| 14 | 1384700059560 |
| 15 | 9692921940280 |
| 16 | 67850518152041 |
| 17 | 474953820774531 |
| 18 | 3324677326552450 |
| 19 | 23272743029259350 |
| 20 | 162909206434992051 |
| 21 | 1140364460735474161 |
[1,11,90,670,4811,34041,239380,1678940,11762421, 82366471,576653870,4036842810,28258696831, 197813269301,1384700059560,9692921940280, 67850518152041,474953820774531,3324677326552450, 23272743029259350,162909206434992051, 1140364460735474161] |