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) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 57 |
| 4 | 509 |
| 5 | 4643 |
| 6 | 43293 |
| 7 | 408211 |
| 8 | 3882871 |
| 9 | 37183105 |
| 10 | 358012837 |
| 11 | 3462520849 |
| 12 | 33613331019 |
| 13 | 327348848723 |
| 14 | 3196657505737 |
| 15 | 31290407955317 |
| 16 | 306922478150245 |
| 17 | 3016082294628575 |
| 18 | 29687026287677819 |
| 19 | 292634127970865519 |