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 | 487 |
| 3 | 4392 |
| 4 | 237655 |
| 5 | 2143287 |
| 6 | 115975153 |
| 7 | 1045919664 |
| 8 | 56595637009 |
| 9 | 510406652745 |
| 10 | 27618554885239 |
| 11 | 249077400619896 |
| 12 | 13477798188359623 |
| 13 | 121549261095856503 |
| 14 | 6577137897364610785 |
| 15 | 59315790337377353568 |
| 16 | 3209629816115741703457 |