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 | 2 |
| 3 | 11 |
| 4 | 47 |
| 5 | 4999 |
| 6 | 4589867 |
| 7 | 1802849 |
| 8 | 80995354865 |
| 9 | 10388318700333839827 |
| 10 | 129530631982136545940863 |
| 11 | 460116344514106299899953231 |
| 12 | 1272711183040784735474188752842879054737 |