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 | -2 |
| 4 | -14 |
| 5 | -27 |
| 6 | 70 |
| 7 | 625 |
| 8 | 1457 |
| 9 | -3541 |
| 10 | -37403 |
| 11 | -98547 |
| 12 | 207098 |
| 13 | 2564079 |
| 14 | 7448923 |
| 15 | -12940485 |
| 16 | -190014459 |
| 17 | -600991549 |
| 18 | 827159379 |
| 19 | 14802832468 |
| 20 | 50584687754 |
| 21 | -52159768068 |
| 22 | -1193457862093 |
| 23 | -4384199208207 |
| 24 | 3090291576246 |
| 25 | 98618925147291 |
| 26 | 388126462227091 |