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 | 3 |
| 1 | 8 |
| 2 | 21 |
| 3 | 56 |
| 4 | 148 |
| 5 | 393 |
| 6 | 1041 |
| 7 | 2761 |
| 8 | 7318 |
| 9 | 19403 |
| 10 | 51436 |
| 11 | 136366 |
| 12 | 361513 |
| 13 | 958413 |
| 14 | 2540831 |
| 15 | 6735996 |
| 16 | 17857733 |
| 17 | 47342548 |
| 18 | 125509476 |
| 19 | 332737401 |