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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 21 |
| 5 | 39 |
| 6 | 51 |
| 7 | 99 |
| 8 | 249 |
| 9 | 261 |
| 10 | 309 |
| 11 | 669 |
| 12 | 729 |
| 13 | 2559 |
| 14 | 2571 |
| 15 | 2619 |
| 16 | 2979 |
| 17 | 3051 |
| 18 | 4239 |
| 19 | 7179 |
| 20 | 7191 |
| 21 | 32589 |
| 22 | 32601 |
| 23 | 32649 |
| 24 | 32661 |
| 25 | 33009 |
| 26 | 33021 |
| 27 | 37209 |
| 28 | 37269 |
| 29 | 37629 |
| 30 | 51489 |
| 31 | 92649 |
| 32 | 92709 |
| 33 | 93069 |
| 34 | 97281 |
| 35 | 272889 |
| 36 | 274509 |
| 37 | 543099 |
| 38 | 543111 |
| 39 | 543159 |
| 40 | 543519 |
| 41 | 543591 |
| 42 | 544779 |