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 | 9 |
| 3 | 18 |
| 4 | 261 |
| 5 | 9432 |
| 6 | 88848 |
| 7 | 236997 |
| 8 | 3792312 |
| 9 | 80803143 |
| 10 | 782822727 |
| 11 | 3454045407 |
| 12 | 36680468013 |
| 13 | 711212421033 |
| 14 | 7929871190046 |
| 15 | 41401704886317 |
| 16 | 358679343516273 |
| 17 | 7546461904118223 |
| 18 | 70046073175181976 |
| 19 | 487736675856414036 |
| 20 | 4236277072800369834 |
| 21 | 60582330255639462183 |