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 | -4 |
| 3 | 6 |
| 4 | 6 |
| 5 | -49 |
| 6 | 95 |
| 7 | 24 |
| 8 | -592 |
| 9 | 1417 |
| 10 | -414 |
| 11 | -6809 |
| 12 | 20142 |
| 13 | -14831 |
| 14 | -73353 |
| 15 | 274761 |
| 16 | -311105 |
| 17 | -715647 |
| 18 | 3607624 |
| 19 | -5463428 |
| 20 | -5785294 |
| 21 | 45588556 |
| 22 | -87189477 |
| 23 | -25565196 |
| 24 | 552659892 |
| 25 | -1305250324 |
| 26 | 340413165 |
| 27 | 6379267117 |
| 28 | -18606431142 |
| 29 | 13202513476 |
| 30 | 69064770845 |