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 | 13 |
| 2 | 86 |
| 3 | 546 |
| 4 | 3768 |
| 5 | 28920 |
| 6 | 246960 |
| 7 | 2333520 |
| 8 | 24232320 |
| 9 | 274700160 |
| 10 | 3378412800 |
| 11 | 44826566400 |
| 12 | 638509132800 |
| 13 | 9720379468800 |
| 14 | 157531172198400 |
| 15 | 2708193616128000 |
| 16 | 49231324606464000 |
| 17 | 943638746738688000 |