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) |
|---|---|
| 1 | 2 |
| 2 | 3 |
| 3 | 5 |
| 4 | 7 |
| 5 | 41 |
| 6 | 47 |
| 7 | 14741 |
| 8 | 14747 |
| 9 | 74747 |
| 10 | 1414741 |
| 11 | 1474141 |
| 12 | 7414741 |
| 13 | 4141414747 |
| 14 | 4147414147 |
| 15 | 14141414141 |
| 16 | 14141414741 |
| 17 | 14141474741 |
| 18 | 14141474747 |
| 19 | 14147414741 |
| 20 | 14147474141 |
| 21 | 14147474147 |
| 22 | 14741414747 |
| 23 | 74141414147 |
| 24 | 74141414741 |
| 25 | 74147414741 |
| 26 | 74741474741 |
| 27 | 74747414141 |