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 | 9 |
| 3 | 35 |
| 4 | 385 |
| 5 | 3717 |
| 6 | 48279 |
| 7 | 691119 |
| 8 | 11229075 |
| 9 | 200982925 |
| 10 | 3928974907 |
| 11 | 83060120871 |
| 12 | 1885501840677 |
| 13 | 45694145548625 |
| 14 | 1176704027583075 |
| 15 | 32077561625780175 |
| 16 | 922854842240358825 |
| 17 | 27951355368760441365 |
| 18 | 889580295850449177975 |
| 19 | 29707539555680924142975 |