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 | 0 |
| 1 | -2 |
| 2 | -10 |
| 3 | -46 |
| 4 | -210 |
| 5 | -958 |
| 6 | -4370 |
| 7 | -19934 |
| 8 | -90930 |
| 9 | -414782 |
| 10 | -1892050 |
| 11 | -8630686 |
| 12 | -39369330 |
| 13 | -179585278 |
| 14 | -819187730 |
| 15 | -3736768094 |
| 16 | -17045465010 |
| 17 | -77753788862 |
| 18 | -354678014290 |
| 19 | -1617882493726 |
| 20 | -7380056440050 |
| 21 | -33664517212798 |
| 22 | -153562473183890 |
| 23 | -700483331493854 |