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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 35 |
| 5 | 728 |
| 6 | 26464 |
| 7 | 1866256 |
| 8 | 251518352 |
| 9 | 66296210432 |
| 10 | 34496477587456 |
| 11 | 35641657548953344 |
| 12 | 73354596197458024448 |
| 13 | 301272202649664088951808 |
| 14 | 2471648811030427594714599424 |
| 15 | 40527680937730480229320939012096 |