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 | 2 |
| 2 | 258 |
| 3 | 6564 |
| 4 | 65540 |
| 5 | 390630 |
| 6 | 1679622 |
| 7 | 5764808 |
| 8 | 16777224 |
| 9 | 43046730 |
| 10 | 100000010 |
| 11 | 214358892 |
| 12 | 429981708 |
| 13 | 815730734 |
| 14 | 1475789070 |
| 15 | 2562890640 |
| 16 | 4294967312 |
| 17 | 6975757458 |
| 18 | 11019960594 |
| 19 | 16983563060 |
| 20 | 25600000020 |
| 21 | 37822859382 |
| 22 | 54875873558 |
| 23 | 78310985304 |