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) |
|---|---|
| 1 | 1 |
| 2 | -12 |
| 3 | 66 |
| 4 | -220 |
| 5 | 495 |
| 6 | -804 |
| 7 | 1068 |
| 8 | -1596 |
| 9 | 3279 |
| 10 | -6952 |
| 11 | 12276 |
| 12 | -17844 |
| 13 | 23653 |
| 14 | -34080 |
| 15 | 57168 |
| 16 | -98428 |
| 17 | 154332 |
| 18 | -215724 |
| 19 | 285388 |
| 20 | -395784 |
| 21 | 600459 |
| 22 | -931888 |
| 23 | 1365696 |
| 24 | -1853076 |
| 25 | 2426189 |
| 26 | -3277896 |
| 27 | 4689534 |
| 28 | -6815008 |
| 29 | 9538632 |
| 30 | -12664440 |
| 31 | 16403188 |
| 32 | -21690876 |
| 33 | 29812932 |