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 | 22 |
| 3 | -194 |
| 4 | 1838 |
| 5 | -18082 |
| 6 | 182054 |
| 7 | -1861890 |
| 8 | 19258078 |
| 9 | -200898626 |
| 10 | 2109785654 |
| 11 | -22275498434 |
| 12 | 236225927182 |
| 13 | -2514344180194 |
| 14 | 26845804973638 |
| 15 | -287403142763522 |
| 16 | 3084015902579646 |
| 17 | -33160937871888514 |
| 18 | 357206218412519510 |
| 19 | -3853959574555396290 |
| 20 | 41640758821142160110 |