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 | 18 |
| 3 | 45 |
| 4 | 90 |
| 5 | 180 |
| 6 | 351 |
| 7 | 450 |
| 8 | 900 |
| 9 | 1800 |
| 10 | 3510 |
| 11 | 4500 |
| 12 | 9000 |
| 13 | 18000 |
| 14 | 35100 |
| 15 | 45000 |
| 16 | 90000 |
| 17 | 180000 |
| 18 | 351000 |
| 19 | 450000 |
| 20 | 900000 |
| 21 | 1800000 |
| 22 | 3510000 |
| 23 | 4500000 |
| 24 | 9000000 |
| 25 | 18000000 |