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 | 0 |
| 3 | -8 |
| 4 | -10 |
| 5 | -44 |
| 6 | -104 |
| 7 | -352 |
| 8 | -1066 |
| 9 | -3564 |
| 10 | -11856 |
| 11 | -40720 |
| 12 | -141284 |
| 13 | -497464 |
| 14 | -1768368 |
| 15 | -6343808 |
| 16 | -22926426 |
| 17 | -83402956 |
| 18 | -305142432 |
| 19 | -1122083312 |
| 20 | -4144811244 |
| 21 | -15372407464 |
| 22 | -57222156528 |
| 23 | -213709942208 |
| 24 | -800563540356 |
| 25 | -3007228179064 |
| 26 | -11325019883616 |