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 | 5 |
| 3 | 25 |
| 4 | 193 |
| 5 | 1601 |
| 6 | 16741 |
| 7 | 190345 |
| 8 | 2509025 |
| 9 | 35825473 |
| 10 | 569012581 |
| 11 | 9716400761 |
| 12 | 180303804385 |
| 13 | 3569527588225 |
| 14 | 75681964322693 |
| 15 | 1700163418683241 |
| 16 | 40499757023856961 |
| 17 | 1016190431274596225 |
| 18 | 26843084299482509125 |
| 19 | 743180975111364212953 |