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 | -3 |
| 2 | 7 |
| 3 | 513 |
| 4 | 13983 |
| 5 | 357857 |
| 6 | 9546255 |
| 7 | 272475249 |
| 8 | 8375575711 |
| 9 | 277269756129 |
| 10 | 9862141508151 |
| 11 | 375700268413577 |
| 12 | 15277275236695743 |
| 13 | 660913009555809345 |
| 14 | 30322968902771794975 |
| 15 | 1471145239418922932193 |
| 16 | 75269422312346702251455 |