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 | 3 |
| 3 | 15 |
| 4 | 97 |
| 5 | 733 |
| 6 | 6147 |
| 7 | 55541 |
| 8 | 530773 |
| 9 | 5298723 |
| 10 | 54780831 |
| 11 | 582817337 |
| 12 | 6350647873 |
| 13 | 70614662303 |
| 14 | 798935833885 |
| 15 | 9176290300419 |
| 16 | 106793746090045 |
| 17 | 1257408517909283 |
| 18 | 14958873368871405 |
| 19 | 179614516459970349 |
| 20 | 2174717049372338913 |
| 21 | 26530091641879493297 |
| 22 | 325875790867387681293 |