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 | 13 |
| 3 | 134 |
| 4 | 1465 |
| 5 | 16106 |
| 6 | 177157 |
| 7 | 1948718 |
| 8 | 21435889 |
| 9 | 235794770 |
| 10 | 2593742461 |
| 11 | 28531167062 |
| 12 | 313842837673 |
| 13 | 3452271214394 |
| 14 | 37974983358325 |
| 15 | 417724816941566 |
| 16 | 4594972986357217 |
| 17 | 50544702849929378 |
| 18 | 555991731349223149 |
| 19 | 6115909044841454630 |
| 20 | 67274999493256000921 |
| 21 | 740024994425816010122 |