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 | 262087 |
| 3 | 22619537 |
| 4 | 457470751 |
| 5 | 4517251249 |
| 6 | 28860511751 |
| 7 | 137379191137 |
| 8 | 528572943487 |
| 9 | 1730726404001 |
| 10 | 4993116004999 |
| 11 | 13007560326001 |
| 12 | 31154649926687 |
| 13 | 69544807113937 |
| 14 | 146217791079751 |
| 15 | 291977237261249 |
| 16 | 557471159562751 |
| 17 | 1023286908188737 |
| 18 | 1814011722210887 |