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 | -6 |
| 3 | -13 |
| 4 | 29 |
| 5 | 120 |
| 6 | -83 |
| 7 | -923 |
| 8 | -342 |
| 9 | 6119 |
| 10 | 8513 |
| 11 | -34320 |
| 12 | -93911 |
| 13 | 146329 |
| 14 | 803706 |
| 15 | -220597 |
| 16 | -5846539 |
| 17 | -4302360 |
| 18 | 36623413 |
| 19 | 66739933 |
| 20 | -189623958 |
| 21 | -656803489 |
| 22 | 670564217 |
| 23 | 5268188640 |
| 24 | 574239121 |
| 25 | -36303081359 |
| 26 | -40322755206 |
| 27 | 213798814307 |