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 | 9 |
| 3 | 23 |
| 4 | 66 |
| 5 | 187 |
| 6 | 529 |
| 7 | 1505 |
| 8 | 4279 |
| 9 | 12167 |
| 10 | 34602 |
| 11 | 98402 |
| 12 | 279841 |
| 13 | 795831 |
| 14 | 2263237 |
| 15 | 6436343 |
| 16 | 18304104 |
| 17 | 52054436 |
| 18 | 148035889 |
| 19 | 420994377 |
| 20 | 1197252007 |
| 21 | 3404825447 |
| 22 | 9682870661 |
| 23 | 27536796143 |
| 24 | 78310985281 |
| 25 | 222706025201 |
| 26 | 633346311282 |
| 27 | 1801152661463 |
| 28 | 5122238579607 |