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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 21 |
| 5 | 51 |
| 6 | 117 |
| 7 | 271 |
| 8 | 607 |
| 9 | 1363 |
| 10 | 3013 |
| 11 | 6643 |
| 12 | 14491 |
| 13 | 31495 |
| 14 | 67965 |
| 15 | 146115 |
| 16 | 312483 |
| 17 | 666015 |
| 18 | 1413915 |
| 19 | 2992815 |
| 20 | 6315135 |
| 21 | 13292007 |
| 22 | 27906585 |
| 23 | 58464339 |
| 24 | 122229123 |
| 25 | 255072423 |
| 26 | 531369483 |
| 27 | 1105217223 |
| 28 | 2295383319 |
| 29 | 4760727375 |