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 | 11 |
| 3 | 48 |
| 4 | 241 |
| 5 | 1358 |
| 6 | 8445 |
| 7 | 57256 |
| 8 | 419233 |
| 9 | 3290202 |
| 10 | 27507349 |
| 11 | 243731084 |
| 12 | 2278919697 |
| 13 | 22402234390 |
| 14 | 230781192301 |
| 15 | 2484462888312 |
| 16 | 27880896280513 |
| 17 | 325432611292082 |
| 18 | 3943062342781605 |
| 19 | 49504837209940612 |
| 20 | 642982531293731761 |
| 21 | 8626753575445207278 |