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 | 3 |
| 3 | 7 |
| 4 | 9 |
| 5 | 19 |
| 6 | 30 |
| 7 | 33 |
| 8 | 39 |
| 9 | 528 |
| 10 | 5040 |
| 11 | 15346 |
| 12 | 25317 |
| 13 | 28320 |
| 14 | 33260 |
| 15 | 158567 |
| 16 | 273271 |
| 17 | 3233048 |
| 18 | 4198629 |
| 19 | 11925231 |
| 20 | 21988969 |
| 21 | 27999429 |
| 22 | 130169953 |
| 23 | 133517597 |
| 24 | 560882700 |
| 25 | 1060718270 |
| 26 | 1158300011 |
| 27 | 1183752951 |
| 28 | 3652709606 |