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 | 10 |
| 2 | 18 |
| 3 | 270 |
| 4 | 360 |
| 5 | 4500 |
| 6 | 5400 |
| 7 | 63000 |
| 8 | 72000 |
| 9 | 810000 |
| 10 | 900000 |
| 11 | 9900000 |
| 12 | 10800000 |
| 13 | 117000000 |
| 14 | 126000000 |
| 15 | 1350000000 |
| 16 | 1440000000 |
| 17 | 15300000000 |
| 18 | 16200000000 |
| 19 | 171000000000 |
| 20 | 180000000000 |
| 21 | 1890000000000 |
| 22 | 1980000000000 |
| 23 | 20700000000000 |
| 24 | 21600000000000 |