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 | 1 |
| 2 | 12 |
| 3 | 370 |
| 4 | 21490 |
| 5 | 2012346 |
| 6 | 276603096 |
| 7 | 52410015372 |
| 8 | 13086020092860 |
| 9 | 4162089324641820 |
| 10 | 1642246641208135248 |
| 11 | 786999935144858519448 |
| 12 | 450157417640763926225496 |
| 13 | 302899153448396612425831800 |
| 14 | 236824761815538353605549389600 |
| 15 | 212892105513043495761147435785040 |