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 | 0 |
| 1 | 1 |
| 2 | -3 |
| 3 | 2 |
| 4 | -6 |
| 5 | -1 |
| 6 | -5 |
| 7 | 132 |
| 8 | 1624 |
| 9 | 17145 |
| 10 | 174509 |
| 11 | 1789842 |
| 12 | 18659146 |
| 13 | 196678143 |
| 14 | 2057524963 |
| 15 | 20460314396 |
| 16 | 171030108768 |
| 17 | 529697015489 |
| 18 | -27050118799923 |
| 19 | -1079945984126798 |
| 20 | -30289996673371254 |
| 21 | -765129844741436785 |
| 22 | -18575997643525737477 |
| 23 | -444653043972658034044 |