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 | -3 |
| 2 | 3 |
| 3 | -7 |
| 4 | 18 |
| 5 | -21 |
| 6 | 30 |
| 7 | -57 |
| 8 | 75 |
| 9 | -104 |
| 10 | 156 |
| 11 | -207 |
| 12 | 293 |
| 13 | -411 |
| 14 | 525 |
| 15 | -712 |
| 16 | 984 |
| 17 | -1248 |
| 18 | 1622 |
| 19 | -2169 |
| 20 | 2757 |
| 21 | -3530 |
| 22 | 4560 |
| 23 | -5736 |
| 24 | 7284 |
| 25 | -9249 |
| 26 | 11472 |
| 27 | -14374 |
| 28 | 18078 |
| 29 | -22242 |
| 30 | 27484 |
| 31 | -34140 |
| 32 | 41787 |
| 33 | -51184 |
| 34 | 62796 |
| 35 | -76317 |
| 36 | 92893 |
| 37 | -112998 |
| 38 | 136275 |
| 39 | -164671 |
| 40 | 199014 |