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 | 2 |
| 3 | 6 |
| 4 | 23 |
| 5 | 93 |
| 6 | 360 |
| 7 | 1312 |
| 8 | 4541 |
| 9 | 15111 |
| 10 | 48854 |
| 11 | 154674 |
| 12 | 482355 |
| 13 | 1487905 |
| 14 | 4553684 |
| 15 | 13857492 |
| 16 | 41998265 |
| 17 | 126912075 |
| 18 | 382702050 |
| 19 | 1152300166 |
| 20 | 3465813071 |
| 21 | 10416313221 |
| 22 | 31288785152 |
| 23 | 93950241096 |
| 24 | 282026883573 |
| 25 | 846449748943 |
| 26 | 2540120998190 |
| 27 | 7621973606682 |