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 | 1 |
| 4 | -6 |
| 5 | 1 |
| 6 | 7 |
| 7 | -79 |
| 8 | 119 |
| 9 | 126 |
| 10 | -270 |
| 11 | 1 |
| 12 | 28 |
| 13 | -515 |
| 14 | 1654 |
| 15 | 8689 |
| 16 | -65864 |
| 17 | 142371 |
| 18 | -82242 |
| 19 | -99090 |
| 20 | 113400 |
| 21 | 1 |
| 22 | 86 |
| 23 | -2255 |
| 24 | 5784 |
| 25 | 300930 |
| 26 | -3904584 |
| 27 | 20663714 |
| 28 | -41517272 |
| 29 | -80232259 |
| 30 | 657717054 |