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 | 2 |
| 2 | 4 |
| 3 | -14 |
| 4 | 35 |
| 5 | -76 |
| 6 | 161 |
| 7 | -357 |
| 8 | 831 |
| 9 | -1955 |
| 10 | 4508 |
| 11 | -10105 |
| 12 | 22168 |
| 13 | -48146 |
| 14 | 104484 |
| 15 | -227391 |
| 16 | 495414 |
| 17 | -1075389 |
| 18 | 2313782 |
| 19 | -4915216 |
| 20 | 10288268 |
| 21 | -21214952 |
| 22 | 43157269 |
| 23 | -86845138 |
| 24 | 173498199 |
| 25 | -345556983 |
| 26 | 689067113 |
| 27 | -1380830712 |
| 28 | 2788197482 |
| 29 | -5680398553 |
| 30 | 11675197082 |
| 31 | -24179658910 |
| 32 | 50364058015 |
| 33 | -105288240165 |
| 34 | 220499927388 |