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 | 3 |
| 2 | 13 |
| 3 | 106 |
| 4 | 1000 |
| 5 | 10315 |
| 6 | 112732 |
| 7 | 1282262 |
| 8 | 15021212 |
| 9 | 179994093 |
| 10 | 2195807684 |
| 11 | 27179964798 |
| 12 | 340514877488 |
| 13 | 4309512389582 |
| 14 | 55014793453124 |
| 15 | 707582318505678 |
| 16 | 9160219144520568 |
| 17 | 119268621622902920 |
| 18 | 1560830776582842660 |
| 19 | 20519083242145870778 |
| 20 | 270851956372499374728 |