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 | 1 |
| 2 | 12 |
| 3 | 126 |
| 4 | 1268 |
| 5 | 12513 |
| 6 | 122148 |
| 7 | 1184364 |
| 8 | 11432100 |
| 9 | 109997460 |
| 10 | 1055891248 |
| 11 | 10117633542 |
| 12 | 96812495820 |
| 13 | 925334377822 |
| 14 | 8836315646616 |
| 15 | 84317468847768 |
| 16 | 804064275489924 |
| 17 | 7663595943744876 |
| 18 | 73009005101019792 |
| 19 | 695263276434909976 |
| 20 | 6618709687608909648 |
| 21 | 62989317586872238689 |