The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 28 |
| 2 | 232 |
| 3 | 1968 |
| 4 | 16832 |
| 5 | 144660 |
| 6 | 1247088 |
| 7 | 10773792 |
| 8 | 93218308 |
| 9 | 807453712 |
| 10 | 6999891340 |
| 11 | 60719731236 |
| 12 | 526944732908 |
| 13 | 4574529170580 |
| 14 | 39722471511860 |
| 15 | 344990169778032 |
| 16 | 2996656884892004 |
| 17 | 26032251950698948 |
| 18 | 226161890813945336 |
[1,28,232,1968,16832,144660,1247088,10773792, 93218308,807453712,6999891340,60719731236, 526944732908,4574529170580,39722471511860, 344990169778032,2996656884892004, 26032251950698948,226161890813945336] |