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 | -9 |
| 5 | 1 |
| 6 | 1 |
| 7 | 91 |
| 8 | 91 |
| 9 | 1 |
| 10 | 1 |
| 11 | -909 |
| 12 | 9191 |
| 13 | -909 |
| 14 | 1 |
| 15 | 1 |
| 16 | 9091 |
| 17 | 918191 |
| 18 | 918191 |
| 19 | 9091 |
| 20 | 1 |
| 21 | 1 |
| 22 | -90909 |
| 23 | 91828191 |
| 24 | -917272809 |
| 25 | 91828191 |
| 26 | -90909 |
| 27 | 1 |
| 28 | 1 |
| 29 | 909091 |
| 30 | 9182728191 |
| 31 | 917364637191 |
| 32 | 917364637191 |
| 33 | 9182728191 |
| 34 | 909091 |
| 35 | 1 |
| 36 | 1 |
| 37 | -9090909 |
| 38 | 918273728191 |