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 | 256 |
| 2 | 65536 |
| 3 | 1679616 |
| 4 | 16777216 |
| 5 | 100000000 |
| 6 | 429981696 |
| 7 | 1475789056 |
| 8 | 4294967296 |
| 9 | 11019960576 |
| 10 | 25600000000 |
| 11 | 54875873536 |
| 12 | 110075314176 |
| 13 | 208827064576 |
| 14 | 377801998336 |
| 15 | 656100000000 |
| 16 | 1099511627776 |
| 17 | 1785793904896 |
| 18 | 2821109907456 |
| 19 | 4347792138496 |
| 20 | 6553600000000 |
| 21 | 9682651996416 |