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 | 6 |
| 2 | 66 |
| 3 | 666 |
| 4 | 990 |
| 5 | 66066 |
| 6 | 69006 |
| 7 | 600060 |
| 8 | 609960 |
| 9 | 690900 |
| 10 | 969606666 |
| 11 | 60690060606 |
| 12 | 96960006066 |
| 13 | 66999966009690066 |
| 14 | 96606660096609006 |
| 15 | 6900969009006996666 |
| 16 | 9906090099969060666906 |
| 17 | 6666999999969090090996690 |
| 18 | 60969009000966690090069999000606 |
| 19 | 660690009096060660069069660609900960960 |