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 | 2 |
| 2 | 3 |
| 3 | 2 |
| 4 | -11 |
| 5 | -30 |
| 6 | 175 |
| 7 | 1010 |
| 8 | -6135 |
| 9 | -60670 |
| 10 | 374875 |
| 11 | 5719650 |
| 12 | -35199875 |
| 13 | -779710750 |
| 14 | 4687746375 |
| 15 | 145208599250 |
| 16 | -836951243375 |
| 17 | -35435177514750 |
| 18 | 191995883837875 |
| 19 | 10975003189933250 |
| 20 | -54688433347786875 |