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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 12 |
| 6 | 33 |
| 7 | 90 |
| 8 | 261 |
| 9 | 766 |
| 10 | 2312 |
| 11 | 7067 |
| 12 | 21962 |
| 13 | 68944 |
| 14 | 218718 |
| 15 | 699423 |
| 16 | 2253303 |
| 17 | 7304522 |
| 18 | 23812437 |
| 19 | 78008885 |
| 20 | 256688310 |
| 21 | 847979474 |
| 22 | 2811399583 |
| 23 | 9351303948 |
| 24 | 31196953900 |
| 25 | 104359901859 |
| 26 | 349979094150 |
| 27 | 1176395410202 |
| 28 | 3962715659611 |
| 29 | 13375015304266 |