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) |
|---|---|
| 0 | 9 |
| 1 | 18 |
| 2 | 99 |
| 3 | 198 |
| 4 | 1089 |
| 5 | 10890 |
| 6 | 20691 |
| 7 | 40293 |
| 8 | 79497 |
| 9 | 158994 |
| 10 | 658845 |
| 11 | 1207701 |
| 12 | 2284722 |
| 13 | 4559544 |
| 14 | 9019098 |
| 15 | 17928207 |
| 16 | 88211178 |
| 17 | 175322466 |
| 18 | 839546037 |
| 19 | 1570191975 |
| 20 | 7362102726 |
| 21 | 13634115363 |
| 22 | 49985258994 |
| 23 | 99970517988 |
| 24 | 188942025987 |
| 25 | 978462275868 |
| 26 | 1847034540747 |
| 27 | 9317488848228 |