This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 6 |
| 3 | 26 |
| 4 | 176 |
| 5 | 1296 |
| 6 | 11296 |
| 7 | 110176 |
| 8 | 1197696 |
| 9 | 14304896 |
| 10 | 186166016 |
| 11 | 2620022016 |
| 12 | 39631568896 |
| 13 | 640971452416 |
| 14 | 11034441916416 |
| 15 | 201411030081536 |
| 16 | 3884642996289536 |
| 17 | 78929236862140416 |
| 18 | 1684881987266215936 |
| 19 | 37695662812132212736 |
| 20 | 881964287274876665856 |
| 21 | 21536903057742987001856 |