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 | -3 |
| 3 | -275 |
| 4 | -15015 |
| 5 | -968167 |
| 6 | -77000363 |
| 7 | -7433044411 |
| 8 | -843598411471 |
| 9 | -107426835190735 |
| 10 | -14072980460605907 |
| 11 | -1424712499632406371 |
| 12 | 164163646840636339593 |
| 13 | 237037449673450822122569 |
| 14 | 155015924346163216960553093 |
| 15 | 92387809011599803660871724021 |