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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 76 |
| 6 | 417 |
| 7 | 2701 |
| 8 | 20199 |
| 9 | 171329 |
| 10 | 1624851 |
| 11 | 17036586 |
| 12 | 195685618 |
| 13 | 2443572835 |
| 14 | 32959210808 |
| 15 | 477542545691 |
| 16 | 7396931591165 |
| 17 | 121976733648960 |
| 18 | 2133460758692093 |
| 19 | 39450254899737811 |
| 20 | 768950119933799815 |
| 21 | 15757352298761474101 |
| 22 | 338663233082663363407 |