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) |
|---|---|
| 1 | 3 |
| 2 | 10 |
| 3 | 21 |
| 4 | 40 |
| 5 | 75 |
| 6 | 134 |
| 7 | 233 |
| 8 | 400 |
| 9 | 683 |
| 10 | 1166 |
| 11 | 1981 |
| 12 | 3364 |
| 13 | 5711 |
| 14 | 9690 |
| 15 | 16433 |
| 16 | 27872 |
| 17 | 47267 |
| 18 | 80150 |
| 19 | 135909 |
| 20 | 230460 |
| 21 | 390775 |