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 | 4 |
| 4 | 13 |
| 5 | -4 |
| 6 | -59 |
| 7 | 848 |
| 8 | 1625 |
| 9 | -57968 |
| 10 | -82679 |
| 11 | 5307072 |
| 12 | 3378277 |
| 13 | -761466432 |
| 14 | -178851763 |
| 15 | 155538255616 |
| 16 | 13323839409 |
| 17 | -43026868334336 |
| 18 | -1145167641071 |
| 19 | 15502018794828800 |
| 20 | 110592144624061 |
| 21 | -7038075176027079680 |
| 22 | -12523284027203883 |
| 23 | 3925127762389637074944 |
| 24 | 1643266949074714633 |
| 25 | -2635567108489125092225024 |