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 | 1 |
| 2 | 4 |
| 3 | 9 |
| 4 | 27 |
| 5 | 74 |
| 6 | 215 |
| 7 | 619 |
| 8 | 1808 |
| 9 | 5293 |
| 10 | 15579 |
| 11 | 45986 |
| 12 | 136141 |
| 13 | 403937 |
| 14 | 1200854 |
| 15 | 3575835 |
| 16 | 10663105 |
| 17 | 31836508 |
| 18 | 95156251 |
| 19 | 284684303 |
| 20 | 852427700 |
| 21 | 2554346249 |
| 22 | 7659427811 |
| 23 | 22981483554 |
| 24 | 68992151795 |
| 25 | 207223579671 |
| 26 | 622697586944 |