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 | 3 |
| 2 | 3 |
| 3 | -6 |
| 4 | 3 |
| 5 | 57 |
| 6 | -141 |
| 7 | -321 |
| 8 | 2460 |
| 9 | -1572 |
| 10 | -29400 |
| 11 | 92505 |
| 12 | 196905 |
| 13 | -1841208 |
| 14 | 1608636 |
| 15 | 24028995 |
| 16 | -85167204 |
| 17 | -161127519 |
| 18 | 1756947801 |
| 19 | -1901675715 |
| 20 | -23476298442 |
| 21 | 91225005105 |
| 22 | 149447955855 |
| 23 | -1890518796654 |
| 24 | 2421742054233 |
| 25 | 25239556328043 |
| 26 | -106352841162777 |