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 | 33 |
| 2 | 153 |
| 3 | 453 |
| 4 | 1953 |
| 5 | 4773 |
| 6 | 19353 |
| 7 | 23253 |
| 8 | 36273 |
| 9 | 37413 |
| 10 | 38793 |
| 11 | 40773 |
| 12 | 50133 |
| 13 | 51693 |
| 14 | 70413 |
| 15 | 70833 |
| 16 | 83433 |
| 17 | 88893 |
| 18 | 108393 |
| 19 | 115233 |
| 20 | 117873 |
| 21 | 131193 |
| 22 | 136113 |
| 23 | 157773 |
| 24 | 161733 |
| 25 | 164793 |
| 26 | 170973 |
| 27 | 184533 |
| 28 | 221793 |
| 29 | 234813 |
| 30 | 238293 |
| 31 | 258453 |
| 32 | 271893 |
| 33 | 272313 |
| 34 | 287313 |
| 35 | 304953 |
| 36 | 307713 |
| 37 | 325533 |
| 38 | 327753 |
| 39 | 330393 |