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 | 28 |
| 4 | 93 |
| 5 | 333 |
| 6 | 1289 |
| 7 | 5394 |
| 8 | 24366 |
| 9 | 118526 |
| 10 | 618924 |
| 11 | 3456942 |
| 12 | 20573391 |
| 13 | 129951231 |
| 14 | 867877107 |
| 15 | 6106194478 |
| 16 | 45109290477 |
| 17 | 348836705235 |
| 18 | 2816093142803 |
| 19 | 23673989688810 |
| 20 | 206794355179656 |
| 21 | 1873232870155036 |
| 22 | 17565534522745008 |
| 23 | 170237112831874188 |