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 | -1 |
| 3 | 5 |
| 4 | -6 |
| 5 | 1 |
| 6 | 125 |
| 7 | -155 |
| 8 | 31 |
| 9 | -1 |
| 10 | 15625 |
| 11 | -19500 |
| 12 | 4030 |
| 13 | -156 |
| 14 | 1 |
| 15 | 9765625 |
| 16 | -12203125 |
| 17 | 2538250 |
| 18 | -101530 |
| 19 | 781 |
| 20 | -1 |
| 21 | 30517578125 |
| 22 | -38144531250 |
| 23 | 7944234375 |
| 24 | -319819500 |
| 25 | 2542155 |
| 26 | -3906 |
| 27 | 1 |
| 28 | 476837158203125 |
| 29 | -596038818359375 |