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 | 3 |
| 3 | -12 |
| 4 | 20 |
| 5 | -45 |
| 6 | 63 |
| 7 | -112 |
| 8 | 144 |
| 9 | -225 |
| 10 | 275 |
| 11 | -396 |
| 12 | 468 |
| 13 | -637 |
| 14 | 735 |
| 15 | -960 |
| 16 | 1088 |
| 17 | -1377 |
| 18 | 1539 |
| 19 | -1900 |
| 20 | 2100 |
| 21 | -2541 |
| 22 | 2783 |
| 23 | -3312 |
| 24 | 3600 |
| 25 | -4225 |
| 26 | 4563 |
| 27 | -5292 |
| 28 | 5684 |
| 29 | -6525 |
| 30 | 6975 |
| 31 | -7936 |
| 32 | 8448 |
| 33 | -9537 |
| 34 | 10115 |
| 35 | -11340 |
| 36 | 11988 |
| 37 | -13357 |
| 38 | 14079 |
| 39 | -15600 |
| 40 | 16400 |
| 41 | -18081 |
| 42 | 18963 |
| 43 | -20812 |
| 44 | 21780 |
| 45 | -23805 |