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 | 9 |
| 3 | 24 |
| 4 | 77 |
| 5 | 198 |
| 6 | 522 |
| 7 | 1550 |
| 8 | 4477 |
| 9 | 12732 |
| 10 | 36214 |
| 11 | 103579 |
| 12 | 296294 |
| 13 | 846303 |
| 14 | 2417368 |
| 15 | 6907329 |
| 16 | 19737901 |
| 17 | 56396602 |
| 18 | 161138214 |
| 19 | 460420182 |
| 20 | 1315565162 |
| 21 | 3758963099 |
| 22 | 10740463083 |
| 23 | 30688703123 |
| 24 | 87686813998 |
| 25 | 250547405698 |
| 26 | 715888629491 |
| 27 | 2045507376543 |
| 28 | 5844625043236 |