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 | 3 |
| 3 | 3 |
| 4 | -8 |
| 5 | -81 |
| 6 | -462 |
| 7 | -1140 |
| 8 | 1662 |
| 9 | 42210 |
| 10 | 341922 |
| 11 | 1588428 |
| 12 | 3968106 |
| 13 | -17035461 |
| 14 | -330216303 |
| 15 | -2645037192 |
| 16 | -15366663001 |
| 17 | -56099904270 |
| 18 | 42126523152 |
| 19 | 2923843607931 |
| 20 | 33032055390075 |
| 21 | 253102960693959 |
| 22 | 1474460670302136 |
| 23 | 5496172108115193 |
| 24 | -8530990617203547 |