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 | 46 |
| 3 | -579 |
| 4 | 8171 |
| 5 | -123079 |
| 6 | 1939421 |
| 7 | -31576204 |
| 8 | 527017546 |
| 9 | -8969076204 |
| 10 | 155054361296 |
| 11 | -2715355794954 |
| 12 | 48068823892546 |
| 13 | -858791527669954 |
| 14 | 15464694800455046 |
| 15 | -280398494896810579 |
| 16 | 5114753787818033171 |
| 17 | -93796371395287435579 |
| 18 | 1728250671451392251921 |