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 | 1 |
| 3 | 5 |
| 4 | 23 |
| 5 | 89 |
| 6 | 484 |
| 7 | 2904 |
| 8 | 22002 |
| 9 | 190555 |
| 10 | 1876337 |
| 11 | 20445337 |
| 12 | 244087420 |
| 13 | 3161870208 |
| 14 | 44155439706 |
| 15 | 661065427533 |
| 16 | 10561205778825 |
| 17 | 179324080364960 |
| 18 | 3224650449785185 |
| 19 | 61218223893368714 |
| 20 | 1223523447160283853 |
| 21 | 25679025453032962132 |
| 22 | 564657001202726477313 |