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 | 2 |
| 2 | 7 |
| 3 | 61 |
| 4 | 863 |
| 5 | 17569 |
| 6 | 472741 |
| 7 | 16007419 |
| 8 | 659408567 |
| 9 | 32231133931 |
| 10 | 1833425773489 |
| 11 | 119498316410171 |
| 12 | 8810846732918257 |
| 13 | 727089137774221667 |