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 | 313 |
| 4 | 3113 |
| 5 | 31413 |
| 6 | 314413 |
| 7 | 3141413 |
| 8 | 31411413 |
| 9 | 314151413 |
| 10 | 3141551413 |
| 11 | 31415951413 |
| 12 | 314159951413 |
| 13 | 3141592951413 |
| 14 | 31415922951413 |
| 15 | 314159262951413 |
| 16 | 3141592662951413 |
| 17 | 31415926562951413 |
| 18 | 314159265562951413 |
| 19 | 3141592653562951413 |
| 20 | 31415926533562951413 |
| 21 | 314159265353562951413 |