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 | -7 |
| 4 | -10 |
| 5 | 27 |
| 6 | 152 |
| 7 | 169 |
| 8 | -949 |
| 9 | -4286 |
| 10 | -2646 |
| 11 | 36499 |
| 12 | 133684 |
| 13 | -376 |
| 14 | -1458768 |
| 15 | -4325495 |
| 16 | 3422105 |
| 17 | 59242995 |
| 18 | 139491393 |
| 19 | -260949134 |
| 20 | -2414487452 |
| 21 | -4307455022 |
| 22 | 15274866472 |
| 23 | 97910544003 |
| 24 | 119082795965 |
| 25 | -805538039024 |
| 26 | -3921641157424 |
| 27 | -2408010178616 |
| 28 | 40104318820288 |