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 | 5 |
| 2 | 21 |
| 3 | 69 |
| 4 | 149 |
| 5 | 69 |
| 6 | -619 |
| 7 | -187 |
| 8 | 9365 |
| 9 | -3515 |
| 10 | -193643 |
| 11 | 453957 |
| 12 | 4704917 |
| 13 | -29425595 |
| 14 | -83918443 |
| 15 | 1640246085 |
| 16 | -3184430955 |
| 17 | -74516517307 |
| 18 | 604223657877 |
| 19 | 1324972362053 |
| 20 | -52526078298475 |
| 21 | 264984579390533 |
| 22 | 2477371363954069 |
| 23 | -44206576595187899 |
| 24 | 133280843118435477 |