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 | 1 |
| 3 | 1 |
| 4 | -23 |
| 5 | -119 |
| 6 | -359 |
| 7 | -839 |
| 8 | 38641 |
| 9 | 359857 |
| 10 | 1809361 |
| 11 | 6644881 |
| 12 | -459055079 |
| 13 | -6175146119 |
| 14 | -43468088663 |
| 15 | -217686301559 |
| 16 | 20051525850721 |
| 17 | 352724346317281 |
| 18 | 3192296431410721 |
| 19 | 20250050516224417 |
| 20 | -2331591425921837879 |
| 21 | -50665325105014242839 |
| 22 | -560439561498466178759 |