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 | 0 |
| 1 | 2 |
| 2 | 5 |
| 3 | 35 |
| 4 | 296 |
| 5 | 2600 |
| 6 | 25317 |
| 7 | 251416 |
| 8 | 2504474 |
| 9 | 25010000 |
| 10 | 250044723 |
| 11 | 2500100000 |
| 12 | 25000316228 |
| 13 | 250002000003 |
| 14 | 2500004472137 |
| 15 | 25000010000000 |
| 16 | 250000044721361 |
| 17 | 2500000141421358 |
| 18 | 25000000316227767 |