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 | 3 |
| 2 | -9 |
| 3 | 15 |
| 4 | -21 |
| 5 | 27 |
| 6 | -33 |
| 7 | 39 |
| 8 | -45 |
| 9 | 51 |
| 10 | -57 |
| 11 | 63 |
| 12 | -69 |
| 13 | 75 |
| 14 | -81 |
| 15 | 87 |
| 16 | -93 |
| 17 | 99 |
| 18 | -105 |
| 19 | 111 |
| 20 | -117 |
| 21 | 123 |
| 22 | -129 |
| 23 | 135 |
| 24 | -141 |
| 25 | 147 |
| 26 | -153 |
| 27 | 159 |
| 28 | -165 |
| 29 | 171 |
| 30 | -177 |
| 31 | 183 |
| 32 | -189 |
| 33 | 195 |
| 34 | -201 |
| 35 | 207 |
| 36 | -213 |
| 37 | 219 |
| 38 | -225 |
| 39 | 231 |
| 40 | -237 |
| 41 | 243 |
| 42 | -249 |
| 43 | 255 |
| 44 | -261 |
| 45 | 267 |
| 46 | -273 |
| 47 | 279 |
| 48 | -285 |
| 49 | 291 |