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 | 3 |
| 2 | 45 |
| 3 | 1008 |
| 4 | 27225 |
| 5 | 819819 |
| 6 | 26509392 |
| 7 | 901402560 |
| 8 | 31818681873 |
| 9 | 1156122556875 |
| 10 | 42985853635725 |
| 11 | 1628541825580800 |
| 12 | 62667882587091600 |
| 13 | 2443473892345873968 |
| 14 | 96351855806554401600 |
| 15 | 3836565846094702507776 |
| 16 | 154071018890153214025473 |