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 | 3 |
| 3 | -6 |
| 4 | 11 |
| 5 | -20 |
| 6 | 37 |
| 7 | -68 |
| 8 | 125 |
| 9 | -230 |
| 10 | 423 |
| 11 | -778 |
| 12 | 1431 |
| 13 | -2632 |
| 14 | 4841 |
| 15 | -8904 |
| 16 | 16377 |
| 17 | -30122 |
| 18 | 55403 |
| 19 | -101902 |
| 20 | 187427 |
| 21 | -344732 |
| 22 | 634061 |
| 23 | -1166220 |
| 24 | 2145013 |
| 25 | -3945294 |
| 26 | 7256527 |
| 27 | -13346834 |
| 28 | 24548655 |
| 29 | -45152016 |
| 30 | 83047505 |
| 31 | -152748176 |
| 32 | 280947697 |
| 33 | -516743378 |
| 34 | 950439251 |
| 35 | -1748130326 |
| 36 | 3215312955 |