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 | 0 |
| 2 | 30 |
| 3 | 138 |
| 4 | 17658 |
| 5 | 414138 |
| 6 | 28493946 |
| 7 | 1246334388 |
| 8 | 72638390592 |
| 9 | 3823498828854 |
| 10 | 218021286182580 |