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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 30 |
| 5 | 653 |
| 6 | 13762 |
| 7 | 304295 |
| 8 | 7251598 |
| 9 | 187783369 |
| 10 | 5287733418 |
| 11 | 161516858963 |
| 12 | 5332258661782 |
| 13 | 189493508862461 |
| 14 | 7219703867130466 |
| 15 | 293780009979371503 |
| 16 | 12721918893479808030 |
| 17 | 584361555380576356625 |
| 18 | 28385640762100638931546 |