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 | 7 |
| 1 | 61 |
| 2 | 601 |
| 3 | 6001 |
| 4 | 60001 |
| 5 | 600001 |
| 6 | 6000001 |
| 7 | 60000001 |
| 8 | 600000001 |
| 9 | 6000000001 |
| 10 | 60000000001 |
| 11 | 600000000001 |
| 12 | 6000000000001 |
| 13 | 60000000000001 |
| 14 | 600000000000001 |
| 15 | 6000000000000001 |
| 16 | 60000000000000001 |
| 17 | 600000000000000001 |
| 18 | 6000000000000000001 |
| 19 | 60000000000000000001 |
| 20 | 600000000000000000001 |