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 | 4 |
| 2 | 64 |
| 3 | 4624 |
| 4 | 26244 |
| 5 | 446224 |
| 6 | 26646244 |
| 7 | 44462224 |
| 8 | 662444644 |
| 9 | 4444622224 |
| 10 | 6266622244 |
| 11 | 26646644644 |
| 12 | 444446222224 |
| 13 | 44444462222224 |
| 14 | 64664242622464 |
| 15 | 624666644462224 |
| 16 | 4444444622222224 |
| 17 | 444444446222222224 |
| 18 | 44444444462222222224 |
| 19 | 64266662664264424464 |
| 20 | 4444444444622222222224 |