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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | -1 |
| 5 | -3 |
| 6 | 0 |
| 7 | 10 |
| 8 | 10 |
| 9 | -28 |
| 10 | -70 |
| 11 | 42 |
| 12 | 348 |
| 13 | 198 |
| 14 | -1353 |
| 15 | -2431 |
| 16 | 3575 |
| 17 | 15587 |
| 18 | 702 |
| 19 | -74698 |
| 20 | -89726 |
| 21 | 264214 |
| 22 | 753236 |
| 23 | -441864 |
| 24 | -4308174 |
| 25 | -2823020 |
| 26 | 18594787 |
| 27 | 36373695 |
| 28 | -52468405 |
| 29 | -249712725 |
| 30 | -24858975 |
| 31 | 1267523445 |
| 32 | 1639209195 |
| 33 | -4671244455 |
| 34 | -14174703810 |