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 | 3 |
| 3 | 15 |
| 4 | 123 |
| 5 | 8613 |
| 6 | 337977 |
| 7 | 169006665 |
| 8 | 40860127671 |
| 9 | 131515599970167 |
| 10 | 201844710508818147 |
| 11 | 4141132208926170478473 |
| 12 | 40464088148356899296269059 |