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 | 24 |
| 5 | 119 |
| 6 | 700 |
| 7 | 4748 |
| 8 | 36403 |
| 9 | 310851 |
| 10 | 2922606 |
| 11 | 29977587 |
| 12 | 332929492 |
| 13 | 3978258079 |
| 14 | 50872884285 |
| 15 | 692985674373 |
| 16 | 10015172966221 |
| 17 | 153021613683924 |
| 18 | 2464031776132958 |
| 19 | 41698912656882644 |
| 20 | 739771703127828419 |
| 21 | 13727160292457369098 |
| 22 | 265876635231121617716 |