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 | 3 |
| 2 | 33 |
| 3 | 303 |
| 4 | 313 |
| 5 | 323 |
| 6 | 333 |
| 7 | 343 |
| 8 | 353 |
| 9 | 363 |
| 10 | 373 |
| 11 | 383 |
| 12 | 393 |
| 13 | 3003 |
| 14 | 3113 |
| 15 | 3223 |
| 16 | 3333 |
| 17 | 3443 |
| 18 | 3553 |
| 19 | 3663 |
| 20 | 3773 |
| 21 | 3883 |
| 22 | 3993 |
| 23 | 30003 |
| 24 | 30103 |
| 25 | 30203 |
| 26 | 30303 |
| 27 | 30403 |
| 28 | 30503 |
| 29 | 30603 |
| 30 | 30703 |
| 31 | 30803 |
| 32 | 30903 |
| 33 | 31013 |
| 34 | 31113 |
| 35 | 31213 |
| 36 | 31313 |
| 37 | 31413 |
| 38 | 31513 |
| 39 | 31613 |
| 40 | 31713 |
| 41 | 31813 |
| 42 | 31913 |