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 | 0 |
| 2 | 254 |
| 3 | 6558 |
| 4 | 65532 |
| 5 | 390620 |
| 6 | 1679610 |
| 7 | 5764794 |
| 8 | 16777208 |
| 9 | 43046712 |
| 10 | 99999990 |
| 11 | 214358870 |
| 12 | 429981684 |
| 13 | 815730708 |
| 14 | 1475789042 |
| 15 | 2562890610 |
| 16 | 4294967280 |
| 17 | 6975757424 |
| 18 | 11019960558 |
| 19 | 16983563022 |
| 20 | 25599999980 |
| 21 | 37822859340 |
| 22 | 54875873514 |
| 23 | 78310985258 |
| 24 | 110075314152 |