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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | -3 |
| 5 | -14 |
| 6 | 63 |
| 7 | 274 |
| 8 | -1383 |
| 9 | -7934 |
| 10 | 50523 |
| 11 | 353794 |
| 12 | -2702763 |
| 13 | -22368254 |
| 14 | 199360983 |
| 15 | 1903757314 |
| 16 | -19391512143 |
| 17 | -209865342974 |
| 18 | 2404879675443 |
| 19 | 29088885112834 |
| 20 | -370371188237523 |
| 21 | -4951498053124094 |
| 22 | 69348874393137903 |
| 23 | 1015423886506852354 |
| 24 | -15514534163557086903 |