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 | 9 |
| 2 | 75 |
| 3 | 627 |
| 4 | 5241 |
| 5 | 43809 |
| 6 | 366195 |
| 7 | 3060987 |
| 8 | 25586481 |
| 9 | 213874809 |
| 10 | 1787757915 |
| 11 | 14943687747 |
| 12 | 124912775721 |
| 13 | 1044133269009 |
| 14 | 8727804479235 |
| 15 | 72954835640907 |
| 16 | 609822098564961 |
| 17 | 5097441295442409 |
| 18 | 42608996659234155 |
| 19 | 356164297160200467 |