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 | 3 |
| 4 | 6 |
| 5 | 15 |
| 6 | 36 |
| 7 | 91 |
| 8 | 231 |
| 9 | 595 |
| 10 | 1540 |
| 11 | 4005 |
| 12 | 10440 |
| 13 | 27261 |
| 14 | 71253 |
| 15 | 186355 |
| 16 | 487578 |
| 17 | 1276003 |
| 18 | 3339820 |
| 19 | 8742471 |
| 20 | 22885995 |
| 21 | 59912931 |
| 22 | 156848616 |
| 23 | 410626153 |
| 24 | 1075018896 |
| 25 | 2814412825 |
| 26 | 7368190921 |
| 27 | 19290113571 |
| 28 | 50502074766 |
| 29 | 132215989335 |
| 30 | 346145696820 |
| 31 | 906220783315 |