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 | 0 |
| 2 | -1 |
| 3 | 0 |
| 4 | 3 |
| 5 | 12 |
| 6 | 35 |
| 7 | 61 |
| 8 | -153 |
| 9 | -2197 |
| 10 | -11330 |
| 11 | -6513 |
| 12 | 576693 |
| 13 | 8039161 |
| 14 | 74592474 |
| 15 | 536729860 |
| 16 | 2823657417 |
| 17 | 5689440944 |
| 18 | -93424479237 |
| 19 | -1452915372079 |
| 20 | -9514285768034 |
| 21 | 42246743764900 |
| 22 | 2340471395600501 |
| 23 | 42987651613157615 |
| 24 | 564523206912685856 |
| 25 | 5656832720379572809 |