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 | 1 |
| 1 | 4 |
| 2 | 36 |
| 3 | 504 |
| 4 | 9576 |
| 5 | 229824 |
| 6 | 6664896 |
| 7 | 226606464 |
| 8 | 8837652096 |
| 9 | 388856692224 |
| 10 | 19053977918976 |
| 11 | 1028914807624704 |
| 12 | 60705973649857536 |
| 13 | 3885182313590882304 |
| 14 | 268077579637770878976 |
| 15 | 19837740893195045044224 |
| 16 | 1567181530562408558493696 |
| 17 | 131643248567242318913470464 |