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 | 7 |
| 3 | 5 |
| 4 | -146 |
| 5 | -351 |
| 6 | 9936 |
| 7 | 51421 |
| 8 | -1394000 |
| 9 | -12844287 |
| 10 | 328407400 |
| 11 | 4874111901 |
| 12 | -115361217696 |
| 13 | -2607873466511 |
| 14 | 55768370301112 |
| 15 | 1866984952934445 |
| 16 | -34886452149332864 |
| 17 | -1720211491314549375 |
| 18 | 26716801597874981064 |
| 19 | 1979492625918149729437 |
| 20 | -23490293022369696366560 |
| 21 | -2777285149336544358953679 |