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 | 0 |
| 2 | 2 |
| 3 | 9 |
| 4 | 32 |
| 5 | 105 |
| 6 | 332 |
| 7 | 1029 |
| 8 | 3152 |
| 9 | 9585 |
| 10 | 29012 |
| 11 | 87549 |
| 12 | 263672 |
| 13 | 793065 |
| 14 | 2383292 |
| 15 | 7158069 |
| 16 | 21490592 |
| 17 | 64504545 |
| 18 | 193579172 |
| 19 | 580868589 |
| 20 | 1742867912 |
| 21 | 5229128025 |
| 22 | 15688432652 |
| 23 | 47067395109 |
| 24 | 141206379632 |
| 25 | 423627527505 |
| 26 | 1270899359732 |
| 27 | 3812731633629 |
| 28 | 11438262009752 |