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 | 0 |
| 4 | -1 |
| 5 | -2 |
| 6 | -1 |
| 7 | 2 |
| 8 | 7 |
| 9 | 9 |
| 10 | 3 |
| 11 | -16 |
| 12 | -39 |
| 13 | -43 |
| 14 | 9 |
| 15 | 126 |
| 16 | 247 |
| 17 | 199 |
| 18 | -213 |
| 19 | -984 |
| 20 | -1555 |
| 21 | -756 |
| 22 | 2525 |
| 23 | 7518 |
| 24 | 9593 |
| 25 | 559 |
| 26 | -24899 |
| 27 | -56216 |
| 28 | -55241 |
| 29 | 33150 |
| 30 | 225879 |
| 31 | 407194 |
| 32 | 273199 |
| 33 | -529745 |
| 34 | -1938549 |
| 35 | -2822128 |
| 36 | -833219 |
| 37 | 6083986 |
| 38 | 15904733 |
| 39 | 18288966 |
| 40 | -4172187 |
| 41 | -61154333 |