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 | 4 |
| 3 | 25 |
| 4 | 218 |
| 5 | 2451 |
| 6 | 33112 |
| 7 | 516727 |
| 8 | 9117180 |
| 9 | 179330905 |
| 10 | 3890434256 |
| 11 | 92271385449 |
| 12 | 2374775505016 |
| 13 | 65900749176835 |
| 14 | 1961009596461840 |
| 15 | 62275489622799751 |
| 16 | 2101798757669917328 |
| 17 | 75111617959762807473 |