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 | -1 |
| 2 | 1 |
| 3 | -5 |
| 4 | 7 |
| 5 | -18 |
| 6 | 30 |
| 7 | -61 |
| 8 | 107 |
| 9 | -199 |
| 10 | 351 |
| 11 | -628 |
| 12 | 1100 |
| 13 | -1929 |
| 14 | 3349 |
| 15 | -5801 |
| 16 | 9991 |
| 17 | -17158 |
| 18 | 29354 |
| 19 | -50085 |
| 20 | 85215 |
| 21 | -144651 |
| 22 | 244991 |
| 23 | -414120 |
| 24 | 698712 |
| 25 | -1176913 |
| 26 | 1979305 |
| 27 | -3323981 |
| 28 | 5574727 |
| 29 | -9337914 |
| 30 | 15623286 |
| 31 | -26111053 |
| 32 | 43594835 |
| 33 | -72716239 |
| 34 | 121181919 |
| 35 | -201779356 |