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 | 1 |
| 4 | 1 |
| 5 | 91 |
| 6 | 541 |
| 7 | 1891 |
| 8 | 5041 |
| 9 | -22679 |
| 10 | 703081 |
| 11 | 9397081 |
| 12 | 59946481 |
| 13 | 510926131 |
| 14 | -1770628859 |
| 15 | 28435376971 |
| 16 | 879567081121 |
| 17 | 1118967005521 |
| 18 | 133425791669521 |
| 19 | -153681150137039 |
| 20 | 1206979480409761 |
| 21 | 974131304609110411 |
| 22 | -2730300052811686739 |
| 23 | 68047061689139820211 |