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 | 5 |
| 3 | 3 |
| 4 | -51 |
| 5 | -190 |
| 6 | -401 |
| 7 | 3672 |
| 8 | 51925 |
| 9 | 151539 |
| 10 | -482538 |
| 11 | -9063614 |
| 12 | -79813421 |
| 13 | -183787112 |
| 14 | 1737820084 |
| 15 | 22402935304 |
| 16 | 179028179329 |
| 17 | 459719628273 |
| 18 | -4012720499801 |
| 19 | -61168331089037 |
| 20 | -556435825634630 |
| 21 | -2299434933774430 |
| 22 | 2674772917888194 |
| 23 | 157684497102084776 |