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 | 514 |
| 3 | 20199 |
| 4 | 283370 |
| 5 | 2256695 |
| 6 | 12637956 |
| 7 | 55247745 |
| 8 | 202345886 |
| 9 | 644749920 |
| 10 | 1846772550 |
| 11 | 4836548836 |
| 12 | 11795957334 |
| 13 | 27022021703 |
| 14 | 58819382790 |
| 15 | 122237638440 |
| 16 | 244429962966 |
| 17 | 471615005229 |
| 18 | 882955864560 |
| 19 | 1606698758560 |
| 20 | 2853601781340 |
| 21 | 4952029001892 |
| 22 | 8423307325854 |