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 | 1 |
| 2 | 3 |
| 3 | 0 |
| 4 | -20 |
| 5 | -45 |
| 6 | 21 |
| 7 | 308 |
| 8 | 540 |
| 9 | -585 |
| 10 | -4235 |
| 11 | -5676 |
| 12 | 11232 |
| 13 | 54145 |
| 14 | 51975 |
| 15 | -182400 |
| 16 | -654160 |
| 17 | -380205 |
| 18 | 2680425 |
| 19 | 7516400 |
| 20 | 1320900 |
| 21 | -36753255 |
| 22 | -82175665 |
| 23 | 24032700 |
| 24 | 477852900 |
| 25 | 850446025 |
| 26 | -749925189 |
| 27 | -5944471092 |
| 28 | -8220606800 |
| 29 | 14049061455 |
| 30 | 71102953305 |
| 31 | 71989187536 |
| 32 | -220682377872 |