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 | 2 |
| 3 | 2 |
| 4 | 6 |
| 5 | 11 |
| 6 | 33 |
| 7 | 86 |
| 8 | 278 |
| 9 | 873 |
| 10 | 2938 |
| 11 | 9904 |
| 12 | 34321 |
| 13 | 119673 |
| 14 | 422725 |
| 15 | 1502590 |
| 16 | 5381671 |
| 17 | 19377063 |
| 18 | 70138385 |
| 19 | 254978018 |
| 20 | 930709334 |
| 21 | 3409356533 |
| 22 | 12530190100 |
| 23 | 46188325542 |
| 24 | 170723964752 |
| 25 | 632624262841 |
| 26 | 2349655631568 |
| 27 | 8745690221340 |
| 28 | 32617408075856 |