| n | a(n) |
|---|---|
| 1 | 20 |
| 2 | 148 |
| 3 | 1088 |
| 4 | 9394 |
| 5 | 85480 |
| 6 | 787412 |
| 7 | 7250142 |
| 8 | 67449574 |
| 9 | 630466648 |
| 10 | 5926141678 |
| 11 | 55929815964 |
| 12 | 529724228140 |
| 13 | 5032227826544 |
| 14 | 47929965246944 |
| 15 | 457554555905322 |
| 16 | 4376712118553570 |
| 17 | 41939283915535994 |
| 18 | 402511337790992824 |
[20,148,1088,9394,85480,787412,7250142,67449574, 630466648,5926141678,55929815964,529724228140, 5032227826544,47929965246944,457554555905322, 4376712118553570,41939283915535994, 402511337790992824] |