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 | 2 |
| 2 | 6 |
| 3 | 24 |
| 4 | 87 |
| 5 | 292 |
| 6 | 959 |
| 7 | 3089 |
| 8 | 9875 |
| 9 | 31410 |
| 10 | 99633 |
| 11 | 315589 |
| 12 | 998889 |
| 13 | 3160340 |
| 14 | 9996605 |
| 15 | 31616816 |
| 16 | 99989509 |
| 17 | 316209268 |
| 18 | 999967330 |
| 19 | 3162219896 |
| 20 | 9999897769 |
| 21 | 31622595517 |
| 22 | 99999679010 |
| 23 | 316227196708 |
| 24 | 999998989804 |
| 25 | 3162275866962 |
| 26 | 9999996815862 |
| 27 | 31622770946248 |
| 28 | 99999989953079 |