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) |
|---|---|
| 1 | -1 |
| 2 | -1 |
| 3 | 11 |
| 4 | 491 |
| 5 | 11159 |
| 6 | -460681 |
| 7 | -103577629 |
| 8 | -8160790429 |
| 9 | 624333860399 |
| 10 | 386787409545839 |
| 11 | 68810049201689531 |
| 12 | -6999828208693648549 |
| 13 | -9872674440874152431161 |
| 14 | -3255253386897615662908441 |
| 15 | 346248578699462435167833491 |
| 16 | 1072454627614122049417452882131 |