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 | 9 |
| 2 | 9009 |
| 3 | 906609 |
| 4 | 99000099 |
| 5 | 9966006699 |
| 6 | 999000000999 |
| 7 | 99956644665999 |
| 8 | 9999000000009999 |
| 9 | 999900665566009999 |
| 10 | 99999834000043899999 |
| 11 | 9999994020000204999999 |
| 12 | 999999000000000000999999 |
| 13 | 99999963342000024336999999 |
| 14 | 9999999000000000000009999999 |
| 15 | 999999974180040040081479999999 |